Police Driveshaft

[Mikeenh]

I just ordered the driveshaft that mensrea gave the part number for in an earlier thread. Fordparts.com sells them for $213.55 with $21.36 shipping. Less than 5 minutes after I ordered by email, I got a call from them to make sure I had the correct part since I listed an 03 MM. Great service & price. The part # is XW7Z-4602-AA It is listed for the Police package.
Thanks mensrea for the part number and thanks tetsu for the fordparts.com connection.
Dealer price $285.88 :mad:

[LincMercLover]

What's that driveshaft rated at (speed-wise)?

[jefferson-mo]

Well guys I just looked it up in my parts catalog and the description for part # XW7Z-4602-AA is as follws:POLICE PACKAGE DRIVESHAFT,METAL MATRIX COMPOSITE

How 'bout them apples?

[buddie]

THANKS GUYS

FIRST TIME POSTING im a new member of the best site on the web .
had my mm for 8 weeks the first MOD will be this driveshaft next will be the chip
also thank you logan great site

[SergntMac]

What gets me really angry, is how LM put this car on the street with a "known problem" part to begin with. They think we're buying these cars to drive 55? Jeeze...

Save your reciepts, guys, may be some reimbursement due after enough of us scream loud enough!

[TAF]

I do enjoy your post and almost always agree with your points. However, I don't think this one is far or valid. I put a Dyno-tech metal matrix driveshaft from Dennis in my car and I couldn't be happier. I don't think the stock shaft is "defective" if there is a remote possibility of a concern @ 120mph. Have I pegged mine a time or two at 140? Yes. would I have done that with a stock MM? No, because it is speed limited in the ECM. Is it crazy to go 140? Yes. (but she sure is smooth there) Are all cars made to go whatever their speedo says? No.

Just wanted to say, I respectfully disagree with any complaint against Mercury on this one. Now, you want to talk about wipers that stink, a "sub-par" sub-woofer that rattles or a sloppy carpet job...I'm with you.

Not a "flame"...just a comment.

[LincMercLover]

The thing is Todd, even with the car at its maximum governed speed, it's still shakey. Here's a car getting A LOT of donations from the PI's, why doesn't it get the driveshaft also? Maybe to deture MM owners from out running the police in stock form? :D

[TAF]

The stock shaft IS better than what had been on a normal GM. I'm just saying that I feel I got what I paid for from Mercury. The other 3 examples I listed are probably better arguements than the drive shaft. I LOVE my Marauder. Even MORE with add-ons from Dennis.

OK..."flame-away" on me. I'm defenseless...getting on a plane and won't be able to log-in for the next 48 hours.

I just don't think IMHO that the driveshaft is as valid of a complaint.

Flame away boys.

[LincMercLover]

Burn baby burn! LOL, no, JP Todd!

[V10_P70]

The Police P71 MM shaft is speed limited to around 130 mph, depends on the final ring gear, 3.27 or 3.55. The top speed has moved from 117 to 130.

[RF Overlord]

If I may:

I, too, agree more with toddalan than with the Sergnt on this one. Other than trained LEO's, very few of us are qualified to drive on public streets at much over the legal speed limit. Now calm down, I'm not suggesting that everyone should "drive 55", I just mean that even if you ARE qualified, MOST people are not, and they won't be expecting you to be barrelling down on them at a buck and a quarter. THAT is what makes it dangerous...

Personally, I didn't buy the Winged Messenger (we're also toying with "Black Falcon") to float like a butterfly at 140 mph. I bought it because, like my SuperCoupe, it's more of a "sleeper"...no one expects that Granddad's boat might actually have some 'nads and might beat them to the next stoplight.

We own a very unusual car here, my friends, and if Ford keeps doing the bang-up job of advertising they have been, we members of MM.net may very well be the ONLY ones...that's OK with me as long as we have people like Dennis et. al. around to support us.

Respectfully...

[mensrea]

I was going to sit this one out... but...If manufacturers build cars that are capable of high speeds I believe they should equip them with the proper hardware. Many cars have speed limiters on them, but isn't this usually due to the tires. If you remove the limiter on other cars, chances are you won't toast the shaft. And for that matter, why make speed limited tires (Z rating is pretty high) However, I don't recall if anyone on here has toasted a tail shaft bearing with stock gears and a chip, so the 4.10s really decrease the critical speed. I guess the moral of the story is when you change the gears, change the shaft. Get em both from Ford and you can't go wrong. With the PI drive shaft I have no "vibration" which I did before. Do I think Ford should pay for my shaft... mmmmmm
And as far as the reliability of the PI shaft, there are a couple of blown vics out there that run em, and they are into the 12s.

[LincMercLover]

I think our stock tires are rated to 167? Where'd I see that...?

[RCSignals]

Actually the Aluminum MMX drivehaft was used in '99-'00 Police Interveptors. The rest use an aluminum shaft. That part number Shaft Ford is selling is a replacement MMX for the '99-'00 Interceptors, so I've been told. So don't feel bad the Marauder driveshaft may well be the same as the current Police Interceptor shaft

[03 Merc]

There is another solution to this "problem" that is cheaper and maybe better than the either the MMX or Dyno-Tech route if you are really concerned. Take your car to a local driveshaft fabrication shop and have the stock driveshaft tested and re-balanced if you need it... The MMX shaft you purchase blind may very well not be any better than the stock shaft on it now.. or as RC pointed out it maybe the same..

If, BIG IF, you have a problem the local shop will fix it..for around $100 to $200.. and you won't be left wondering if you just tossed money at something that wasn't an issue... If it was a issue you know it was fixed right not just replaced with an unknown...

The local SVT dealer (Team Ford) I talked to about doing my mods recommended two local shops.. Check your yellow pages and save some money...

BTW Todd if you miss breakfast tomorrow we will "flame" you real time then...:D

[mtnh]

Are the U-joints any better on the upgraded shafts? I thought that I had read that someplace. I also recall that post where the gent ran it at 125 and the stock shaft wobbled so much that the rear transmission seal walked out of its landing. Holy s, what a way to toast a transmission!

Mike

[mensrea]

OK, maybe I misunderstood the above post... but our shaft is not the same as the MMX shaft for the 99-00 PI. The part number above is actually a MMX shaft, and again I have this in my car and it works great, even at higher speeds.

My goal in bringing this up originally was to try and save you guys some money, no use spending 450 when 250 would do. Now I know you are thinking, this guy's nuts, he spends tons of money on a conversion then balks at an extra 200 bucks... I will gladly pay for something that has a tangible benefit, but why spend money when you don't have to?

It is the tailshaft seal and carrier that craps out... here's a pic I lifted from another site. (FYI the label tranny housing is really tailshaft housing)

Tailshaft seal failure (http://www.mercurymarauder.net/gallery/details.php?image_id=117)

[SergntMac]

I think a few of you may have misunderstood me, and that's my fault for not being clear. I was venting on the probability of a design flaw, or, production line screw up in early builds. Mensrea seemed to hear me the best.

We were "sold" a high performance driving machine, the best of the goodies from FMC parts bins, and one or two new design thoughts as well. Did we get the correct part for a performance car or not? Doesn't look that way right now, does it.

National speed limits are 65, and my experience is that most road rebels cruise 9-10 mph over that, just enough to be maintain the rebellion, but not enough to draw serious attention. Hold that thought a moment.

A while back in another thread, drive shaft vibration was explained in very technical terms by one of on board experts. I didn't get it all under my hat, but my understanding now, is that because of my gear change, I may expect vibration to develop at 70-75. MPH. Then again, I could have misunderstood the lesson.

Now, if I'm cruising in the 70's for long drives, should I expect this vibration, however subtle, to shorten bearing and seal life due to minimal but constant imbalance? Can this be detected on a dyno?

I don't know what to do, I feel nothing I can differentiate from routine road noise. But, I believe in preventive measures, and I can avoid eating a tranny by upgrading the shaft, I'd probably upgrade. I would like to know what the car came with, and it's substandard across the board, LM/FMC should do the right thing. As it has been mentioned, the FMC/MMX shaft was a corrective measure for earlier CV/PIs, maybe we that already, and just a few of us got poorly balanced shafts.

If this is a design/production slip up, maybe we all got the shaft...

[mensrea]

For those of you who missed the original link... here is the article that describes critical driveline speed. I suggest everyone read it.

Driveline Critical Speed information (http://www.tccoa.com/articles/tranny/transmission/page17.shtml)

[LincMercLover]

If you're getting vibration at 70-75, you definately have a messed up shaft. I've cruised 90MPH, bone stock, and felt no vibration what-so-ever. I don't see a 4.10 gear change affecting the spin rate of the driveshaft that much to cause noticeable vibration. I think our best bets are to go with the PI MMX driveshafts. It's cheap, and a Ford part.

[smith5365]

Years back when running my Shelby Mustang between Scottsdale, AZ and Tustin, CA., I did a lot of triple digit indicated runs between Blythe and Indio (before freeway). I had drive shaft vibration big time! Had it staightend and balanced which helped immensely. I know this is a must from my point of view anytime we run higher rpms on the shaft. The high speed lane on our local freeway runs at 75 to 80. There are some that run faster. I know I'll change the shaft, have it staightend and balanced just to ensure long life for the entire trans to diff pieces.

Bill Smith

[03 Merc]

SergntMac,

I think the key to your "vent" lies in your post...a couple of "out of text" quotes...

Quote: "is that because of my gear change, I may expect vibration to develop at 70-75. MPH."

Quote: "I would like to know what the car came with, and it's substandard across the board, LM/FMC should do the right thing."

LM/FMC did not engineer your car with 4.10's, you did... I don't disagree with your reasoning for doing it nor with your opinion that they should have themselves due to the marketing around the car.. but they didn't. So if the production shaft was designed for, and sufficient for, the car as sold, in the North American market with it's constraints (Speed Limits) they have already done the "right thing"... like someone said in another thread if you start making changes you need to look for the next point of failure...

BTW there hasn't been a national 65mph speed limit for a few years now..speed limits are set by the states see: http://www.iihs.org/safety_facts/state_laws/speed_limit_laws.htm since some states are 75mph I suspect the car was engineered to that number plus...

Good Luck chasing LM on this one...

[mensrea]

What the hell is the point of this thread anymore....

[LincMercLover]

I'm guessing to prove it ISN'T LM/FMC's fault for the crappy driveshaft?

[Mikeenh]

Amen mensrea,
If you are concerned about your shaft, here was an inexpensive fix with FORD parts. If you don't have a chip, don't worry about it.
Logan....time to close this one up. We're going in circles :confused:

[mensrea]

Did someone say that the driveshaft might be bad in my car....

[LincMercLover]

I JUST DON'T GET IT, CAN SOMEBODY RE-EXPLAIN?!?! *Banging head on monitor* :D

[Dave Compson]

I want to know if this cheaper ford driveshaft will perform the same way the reinheart shaft does. If so, count me in. I think thats what this threat started about. Now its on some tangent on speed limits and such.

Let me know how the replacement ford shaft works.

Dave

[tetsu]

The shaft from Dennis is balanced up to 6k rpm and includes some h/d u-joints if I recall correctly.

Johnny

[jefferson-mo]

You know if you DO have a vibration take it to the dealer under your warranty. If your dealer will work with you ask them to put the PI shaft in. That's my plan.

[mensrea]

Ahhhhhhhhhhhhhhhhhhhhhhhhhh

OK, this is getting crazy... LML I was kidding.

The shaft Dennis sells is manufactured by DynoTech drive shafts, he does not make it himself. Here's their web page, although his price may be competitive.

Dynotech Drive shaft (http://www.dynotechengineering.com/)

do you really think I would put a crappy driveshaft in my car? I have one of the few supercharged marauders in private hands...

I am not telling anyone what to do, but I have had no problems with my shaft... and I have around 400 RWHP.

If you've got the money to burn, buy the DynoTech. If you want a drive shaft that works, and is half the price, buy the PI.

Now can we move on to something exciting like putting FR500 heads on our cars now that the valve train is available... or how about that five speed transmission in the Aviator.

[Heavy351]

03 MERC is on the money here. Assuming the driveshaft and joints can handle the torque from the motor the only other issue is balance.

The reason some of you feel it and some don't is more likely to do with Ford being hit or miss on their spin balance work. The PI shafts may get a bit more scrutiny before the go out ( or maybe they are done somewhere else entirely) I see dynotech also can do the multi axis balancing themselves. spin balancing the stock shaft should work great (mensrea would probably be pushing the limit though)

Driveshaft harmonics also have to do with the stiffness of the Tranny mount, CV joints, and the way the 8.8 is held. one of the low frequency mode shapes from the shaft could exite other components too.


The CVPI and the MM driveshafts are shorter than stock to raise the first bending mode frequency high enough to not vibrate any other driveline components at 130mph. Shorter=stiffer and more tolerant if dinged or abused like copcars are sometimes. The critical speed is usually multiple times the max RPM of the motor (at least on most machines)

As I mentioned on the other thread, I have the software to compare stock frequency response to the PI or dynotech's shaft if I can get some measurements.

[Logan]

It should also be noted the dynotech shafts are made of a thicker stock than the stock shafts and can handle a higher torque load without twisting in half.

[schuvwj]

Does any one know what the RPM of a MM is at 60 MPH and at top speed with 4:10 gears?

[ONEBADMK8]

The Dynotech is thicker then the factory Ford PI MM unit?

[SergntMac]

Bill...

I have 4:10s and a chip. I ran a few "tests" for you. I kept my MM in 3rd gear, OD off, for a true 1:1 drive line ratio. What's on my tach, should be the RPM of my drive shaft, yes?

If so, this is what I have observed with my MM.

60 MPH is just shy of 3000 rpm. 3000 RPM is about 62 MPH.
70 MPH is just shy of 3500 rpm. 3500 RPM is about 68 MPH.
80 MPH is 4000 rpm and 4000 RPM is 80 MPH.

[SergntMac]

Just an afterthought to my last post...

This thread is really messed up, lots of "flotsam and jetsam," know what I mean?

Anyone wishing to begin anew, begin.

[Directedby]

What is the rpm with the 3:55 gears at 60mph?

[SergntMac]

Get your own MM and look for yourself, okay?

jeeze...

[SergntMac]

Sorry...I was out of line here.

Start a new thread, please?

[Directedby]

Is this board exclusively only for MM owners?

I am asking questions because I am excited about buying this car and upgrading it.

Jeeeze is right.

Merry x-mas...bah humbug Sarge.

[Murader03]

Originally posted by Directedby
Is this board exclusively only for MM owners?

I am asking questions because I am excited about buying this car and upgrading it.

Jeeeze is right.

Merry x-mas...bah humbug Sarge.

I don't think this board nor any other is exclusive. If you have an interest, then your welcome to this and any other borad that I've ever been on. Welcome aboard!

[SergntMac]

[Mikeenh]

Directedby,
I was going to go out and check the rpm's for you , but we just started a storm where we will get 12 to 18 inches of snow ....so here's a site that you can check that should answer all your questions. Happy Holidays
http://www.averagegeek.com/Evil_Jim/GearCalc.asp

[Murader03]

Sarge! AMEN!

One suggestion I have to ALL! You've said your peace, we all enjoy the board, so let's try and keep it civil. I left both BON and CVN because they were nothing but attacking each other or doing the one-up-manship. If you want to carry on a negative dialog with each other then take it private via email, or better yet trade phone numbers and that it vocal. Get you differences ironed out., keep it off the board. Life's to short for the BS.

[Billatpro]

So whats the RPM at 32 MPH in reverse, I've never had the guts to look at the tach!

[Billatpro]

I forgot to say that was just a joke guys.

[tetsu]

Hey Sarge,

You were the dude who was talking down to me about how you wouldnt waste your time doing your own auto work cuz you make so much more than a measley $90/hour L/M shop charges.

DirectedBy asked a legit question and you jumped his ass for no good reason. Then, you tried to make up some cockamaney crap to cover up your own lousy words. Then on top you call him a "Typical Hollywood Prick."

"Feh" to you dude. That's all I have to say.

Oh yeah, next time I hit the highway DirectedBy, I'll give you the rpms.

Johnny

[Pantherman]

One thing needs to be kept in mind here. The CURRENT production police shaft won't raise your critical speed. The only higher speed shaft in the Ford parts system is the metal matrix shaft used for a short period on 3.55 rear axle police cars.

[SergntMac]

I never talked down to you, Johnny and if you feel that way, you have misunderstood the text. This is one dimensional medium that can be problematic when making a point, and I try to be as clear as I can. Nonetheless, you feel wronged, and I apologize.

I would have preferred to e-mail you, keep this off the board, but you have that turned off in your profile. Moreover, we will again disagree about something else I'm sure. I expect to be treated in the manner I present myself, and you will have that courtesy returned as well. Feel free to contact me if you feel slighted again. My comments to DirectedBy, would have been made off the board if he too did not have his e-mail turned off. I spoke out of turn to DirectedBy, and I did apologize, almost immediately. I treat others as they treat me, I don't often turn the other cheek.

The quote you refer to about wages;

"Could I have saved money here? You bet. But, I don't work on cars anymore, I just drive the s***t out of them. And, I earn more per hour than I would have saved in doing this work myself or shopping out the least expensive wrench."

This is not a brag of what I earn. What it says is that I included my time in the cost of mods equasion. The length of time it would have taken me to accomplish these mods myself, is down time for the car and time away from income producing work. Add that up, and it's was cheaper for me to hire a pro get my MM back in just a few hours, rather than days. That's all it says, Johnny.

I'm at 312.745.5207, 6AM to 2 PM, if anyone is interested.

[SergntMac]

Here's what I've learned about drive shafts, mostly from a LM parts depot.

CV/PI and Taxi get a 3W7Z-4602-EA drive shaft at production

GMs with a "sport package" get 3W7Z-4602-DA

MMs have their own drive shaft, 3W3Z-4602-AA

I think it's safe to presume that the drive shaft from the factory is considered durable, but individual balancing may be the culprit if your getting vibration.

[Directedby]

Sarg and others:

I am sorry this has caused a stir. I have been really impressed with the people here. You all seem very nice and very committed to the MM.

Sarge, in my defense, I was just asking a question about the gears because I am going to buy the car, so I get excited about all the options and what they can do or what their limitations are. I also think I have opened other topics other than 'leasing' which have contributed to this board. I believe you even said 'I love this board' on a link I started.

I am not a 'Hollywood Prick'. I am a proud father, husband, son and brother and I love my job as a producer and direcor. Do not jump to any conclusions, Sarge.

Sarge, I emailed you several days ago (before our tassle), via this website.

If you did not get it or want to email me directly please do so at:

PAK@thekaufmancompany.com

Thanks, and let's drop all the negativity.

[RCSignals]

Originally posted by SergntMac
Here's what I've learned about drive shafts, mostly from a LM parts depot.

CV/PI and Taxi get a 3W7Z-4602-EA drive shaft at production

GMs with a "sport package" get 3W7Z-4602-DA

MMs have their own drive shaft, 3W3Z-4602-AA

I think it's safe to presume that the drive shaft from the factory is considered durable, but individual balancing may be the culprit if your getting vibration.

Only thing I see wrong with what they told you is the Taxi does not get the same tail shaft and aluminum drive shaft that the PI does. Taxi gets the same steel driveshaft and shorter tailshaft as the regular CV

The MM gets the same tail shaft as the PI, and the aluminum driveshaft itself may also be the same.

Out of curiosity i looked up price of the various drive shafts on fordpart.com

3W3Z-4602-AA $248.82 list

3W7Z-4602-DA $248.82 list

3W7Z-4602-EA $365.33 list (described as "3.50 1" )

oddly none specifically state aluminum or steel

the MMX shaft XW7Z-4602-AA $285.88 list (described as "3.55" )

still did not indicate Aluminum MMX even though it is

[JAL]

Hey Carnutt,

What does your posting this in every section of the forum accomplish?

Take it up with him and leave us out of it.

I want to read about drive shafts, not your complaints.

Jeff

[LincMercLover]

Sergnt,

LOL, not to sound like I'm being a smart ass (cause I like you and I've agreed with a lot of your points) but, that's what the little "edit" button is for... :D

However, I do agree that this thread is getting WAY to long and falling out of it's origanal topic. Top end ratios and RPM in certain gears SHOULD go to another thread.

Simply stated, our mad-man with the blown MM says the PI shaft is doing him fine. So I'd imagine it's MORE than adequit enoph for a Reinheart packaged MM. IF you happen to have the bux, then pop for the MMX... plain and simple, why beat around the bush?

And carnutt, GO AWAY!

[JamesHecker]

Wow...catching up with this thread was just exhausting!

[schuvwj]

Sorry Guys I think I started the mis-direction of this thread from drive-shafts to gears and speed. I'll try to keep it straight!

[SergntMac]

For the record, gentleman.

I've been in touch with DirectedBy via e-mail, and he seems a genuine gentleman after all. My apology has been made, but regardless of my reasoning or motovation to post my comments, I was wrong to engage in name-calling. That was disrespectful to all of us here, and it will not happen again.

SergtnMac.

[SSMOKEM]

Now for a view from the other side :)

The Impalas come with a 3.08 gear, so generally driveshaft vibrations don't occur, even at the average top speed of around 140/145 or so.

However, once we change to 3.73+ gears, then 90mph seems to be an average point where vibrations start. I would guess 70% of the higher geared Impalas get these vibrations.

We generally like the MMX for Dynotech for a few reasons:
1) 3.5" diameter, a bit thicker wall and the composite ceramic/aluminum material really moves the onset of vibrations quite high in the RPM range.
2) The Dynotech driveshafts are VERY strong. All of our top runners are using them, and these are cars in the 900 crank HP range.
3) My own car puts out over 700lb.ft. of torque, and even at 6500 driveshaft RPM, I have NO vibrations of any kind (3.73 gears).
4) They are lighter than our steel stockers and remove some rotating mass.
5) Our guys that change over to the T56 manual 6 speed, generally opt for the 4.56 gears. The Dynotechs still don't vibrate, which is amazing, because at at 120mph with a 4.56 and 26" tires, the shaft rotates at 8000 rpm!! The reason most of these guys change to the 6 speed is they like to drive at VERY high speeds.

In our local club, we would buy no other driveshaft.

By the way, the officially fastest Impala ran 193mph in Germany on the Autobahn, clocked by police radar. He also uses a Dynotech. (no ticket, though!!)

[SergntMac]

Wow...thanks George, very interesting stuff.

I just found this site and it spells out some interesting things in plain talk. You guys with sub-woofer issues ought to check here too.

I don't know if this will come up as a hot key or not, you may have to cut and paste to your browser.

http://home.hiwaay.net/%7Ectfrench/Driveline%20Vibration.htm

[bnvus]

By the way, the officially fastest Impala ran 193mph in Germany on the Autobahn, clocked by police radar. He also uses a Dynotech.

Good point George. What if 1 of the MM's wind up in Europe? I am a service member and COULD be there next year (with my new Marauder HeHeHe). Average cruising speed on the Autobahn is 100. Certainly don't want to run into any "bad vibes" over there.

Sorry had to go there. The positive side of this thread is getting the information out there. An alternate driveshaft is available from Ford and a good website is available to check for parts.

Speaking of parts...I have an alternate source of parts for you. I have dealt with Bill Jenkins over the internet a few times to purchase parts for a few people. He comes from the Contour.org board. For all the doityourselfers he might be able to save you some money.

parts@signaturelm.com or call 1-800-876-3280. Bill moved to this new dealership in Las Vegas June 2002 from Sentry Auto Group in Boston.

[mungce]

When I e mailed Dennis Reinhart about his drive shaft, he mentioned that it was set up for the 4:10 gearing. I din't know that drive shafts were set for a specific gear ratio, or are they ? On the Ford P71 shaft, is it also set for specific gearing? If so, what ratio ? I am wanting to purchase in the next few weeks and your input is always welcome. I have yet to decide on if I am going to the 4:10 set up. Logan has told me that he would show me the differeance at the next meet in Dallas, I have yet to attend. How about the speedo and it's reading when a gear change is made ? Is there a part to replace to standard one with OEM ratio gearing, or is it something you just gotta remember. I read Logans tech report on the speed differential, when uping the geras to 4:10. I am sold on the chip, plugs, thermostat, and will be ording them very soon. I know that I want a " reliable" drive shaft, and Dennis makes a good one, from all that I have read. Any major differences between the P71 and his ?

[tetsu]

Shafts aren't designed for certain gearings, but the idea is that Dennis likes the dynotech because he knows it will stand up to the test at rpms up to 6k. If you go with 4.10s and chip it, you will be able to run up around 6k rpm in 3rd gear.

The dynotech shaft is prebalanced up to 6k rpm according to Dennis' site. It's thicker also and I believe comes with heavy duty u-joints.

If you add in a balancing job and u-joints to the cost of a dynotech, you find that you are paying slightly more for something that can probably take more twist (if you are planning on reaching for the sky.)

I wouldn't be comfortable with the Ford MMX shaft if I was going to go any more extreme than mensrea has. If I was going to bother putting one on though, I would get it balanced and upgrade the ujoints at the same time regardless.

OH YEAH.....whether you are going to replace the shaft or not, I would give considerable thought to spending $50 to have a driveshaft loop put on.

With all the talk about driveshafts, I've really been paying attention to my driveline's vibrations above 5k rpm. I can notice some vibration.

Johnny

[RCSignals]

mungce, the Ford Aluminum MMX shaft for cvpi is stated as for 3.55:1 ratio.

[billwork]

Guys,

I was cruising this forum today and was curious to see what the Ford catalog said. When I looked it up it showed being replaced by a new part #.

4W7Z-4602-AA List $182.95 MMN $137.21
plus S&H.

Old part # XW7Z-4602-AA List $301.38

Now that is a nice price reduction.

if you want to order one, just call me at the 800 #below, or visit this link

http://www.signaturelm.com/frameset1.asp?LINK=Parts&MAIN=parts_wildcard1 (Signature L/M parts counter express)

[SergntMac]

Dayum, had ya waited ten more days, you could have resurrected a one year old thread. I think we got a prize for that around here somewhere...Oh yeah, here it is. One year free access to MM.Net. Sorry, Billworks, going to have to disqualify you now...

[bugsys03]

That was good reading. How some things have changed in 1 year

[billwork]

Dam I was hoping on winning that prize :-)

Should I start a new thread for this?

Someone may want this.

[joflewbyu2]

billwork, are the 2 part #s the same driveshaft or different? I believe the old part # was a police metal matrix metal driveshaft and the newer one is an aluminum shaft. The older one should say mmx-police in small letters while the newer one says police in big letters. pics of each could help me as well as others in ordering the shafts.

[billwork]

I have one on order and should know more Friday. It shows that the orginal XW7Z was replaced by the new 4W7Z one.

I went online to Ford and checked the weight of all 3 shafts listed. The OEM is 26lbs, Taxi is 32lbs, and the MMX was 19lbs.

I will post photos when it arrives.

[Dennis Reinhart]

The whole purpose of the drive shaft upgrade is to safely exceed the 123 MPH range, you cannot do that with out a programing change, now if you install 4:10 gears you have dramatically lowered the critical drive line speed way under 123MPH, even with the police shaft. The police shaft is not made for this. Police cars are geared totally different, if the police shaft was OK don't you think it would have been installed in our cars to begin With?? and the top speed limiter raised. Lastly for those of you that don't know PI CV cars shut down at 128 MPH.

For those members that were at Ennis you got the truth, the whole truth and nothing but the truth, from Steve Babcock, the only way to safely do this is with a MMDS that was designed and balanced for high speed usage, by Dynotech, Don't take my word on this, call Jim at Jvillalpando@dynotecheng.com 248-362-2777 ask him about the Police shaft as compared to the shaft that I had made for our cars.

yes it costs more but its worth it, there is an old saying you get what you pay for.

[Zack]

This thread was started one year ago.
I had my MMX Driveshaft on 2 months already,
AFTER I blew the tailshaft seal out at 125mph.

[RCSignals]

Originally posted by billwork
When I looked it up it showed being replaced by a new part #.

4W7Z-4602-AA List $182.95 MMN $137.21
plus S&H.



is that the drive shaft for the '04 CVPI with 3.55:1 gears, and is it aluminium MMX, complete with yoke and universal joints?

[billwork]

I will not know until Friday when I get it in. It is for the 1999-2003 models. My catalog does not list one for 2004 yet. But I will call Ford to double check.....
,,,,,
,,,,,

Well they said I need the VIN from a 2004 PI to verify this.

Anyone got one?

[jefferson-mo]

Yeah let me know too........I still have one of the old ones in stock....XW7Z-4602-AA

My guess is the 4W7Z is not MM....................

[Hemlock]

LOTS OF RUNS 140



































































































































































































































































































































































































































LOTS OF RUNS AT 140+ WITH DRs SHAFT , ITS WORKED JUST FINE FOR 41,000 MILES . BUY IT , AND YOUR WORRIES ARE OVER !!

CHEERS!!



=

[VaderSS]

Some things to keep in mind, maybe they have been covered...

RPM of the driveshaft will be the same RPM as the engine, when in D, not OD. In OD, the shaft wil be spining some multiple faster than the engine. Divide 1 by the OD ratio to get that multiple. 1/.7 = 1.429 in the case of the 4L60E.

Critical speed has nothing to do with balance. Give the shaft a perfect balance, it still has the same critical speed.

Vibrations can happen below the critical speed. These vibrations have nothing to do with the critical speed, but have to do with balance and/or resonance.

You may be able to exceed the critical speed of your driveshaft with no problems, but the moment you do, you have the very real possibility of a catastrophic failure, with zero warning.

[Dennis Reinhart]

Originally posted by VaderSS
Some things to keep in mind, maybe they have been covered...

RPM of the driveshaft will be the same RPM as the engine, when in D, not OD. In OD, the shaft wil be spining some multiple faster than the engine. Divide 1 by the OD ratio to get that multiple. 1/.7 = 1.429 in the case of the 4L60E.

Critical speed has nothing to do with balance. Give the shaft a perfect balance, it still has the same critical speed.

Vibrations can happen below the critical speed. These vibrations have nothing to do with the critical speed,


This part you are wrong, critical speed is where the drive shaft actually flexes in and out, and sets up a harmonic this is due to the metal composition of the drive shaft, now if the drive shaft is out of balance it can vibrate at any speed, the drive shaft on the stock Marauder reaches critical speed above 123 MPH with 355 gears that's why the car is governed, the MMDS is made of superior composite metal matrix aluminum, and spun balanced to 6000 rpm I have posted the technical article several times about critical drive line speed, maybe someone here can post the link for you.

but have to do with balance and/or resonance.

You may be able to exceed the critical speed of your driveshaft with no problems, but the moment you do, you have the very real possibility of a catastrophic failure, with zero warning.

[VaderSS]

All of what you state is correct and not refuted in my above post.

I just want people to understand that balance and critical speed are two different things. I'm guessing you have already explained that. Critical speed is a function of the physical properties of the DS, including material used, wall thickness, diameter, and length, and not of the balance. Out of balance will be detected as vibration and rarely results in a failure without warning. The driver may chose to ignore the warning, but it is still there.

Critical speed can be exceeded, in some cases, with no warning, so the driveshaft can fail without any warning.

[Dennis Reinhart]

They know this, since its been disscused many many times.

What it is –
Every rotating object has a “critical” speed or resonant speed, which is a function of its design, mass and stiffness. This is when the driveshaft is whipping in the middle, rather than spinning on a true centerline. For a driveshaft, this is also called “first bending mode”, indicating the shaft actually bows out into a boomerang shape (on a micro-scale). This first mode bending speed is usually referred to in a driveshaft frequency.

What it does –
The energy stored and released through the deflection of the driveshaft through the resonance creates lateral and vertical accelerations of >10g at the problem frequency, which results in broken transmission extension housings, cases and causes moderate to severe vibration at highway speeds (> 70 mph), particularly with axle ratios numerically higher than 3.27:1. This energy release, when compounded by excessive driveshaft imbalance (some is good, too much or too little is not), companion flange run out/imbalance and excessive driveline angles provides the driver with excessive vibration and boom and tortures the driver and driveline components in general.

Because of this, most vehicles have a speed limiter to prevent from entering this mode and causing damage to the driveline.

Some detail –
As mentioned above, the driveshaft rotates at a certain speed based on rear axle ratio; tire size and road speed, but is independent of engine speed (unless you have a vehicle such as a Porsche 944 or C5 Corvette which utilize torque tubes and transaxles, in which case the driveshaft turns at engine speed).

The factors governing driveshaft critical speed include its material properties (i.e., Bulk Modulus of Elasticity which is roughly analogous to material stiffness), diameter, and length and to a lesser degree, wall thickness.

The only factor you can really modify to affect critical speed is material choice. Length is package-dictated, and diameter is usually constrained by driveline tunnel space as well. The answer then becomes a bit simpler – replace your steel shaft with an aluminum or MMC (metal matrix composite) shaft. Both offer reduced weight, which is key in this frequency range. MMC offers the additional bonus of additional damping and stiffness over a typical aluminum alloy.

As mentioned above, at the frequencies in question, a change in rotational mass has a greater impact on resonant frequency than a change in stiffness does, partly since it is easier to reduce mass than increase stiffness (adding stiffness almost invariably means adding mass -- a vicious circle), but particularly since resonant frequency is equal to the sqrt (k/m), where m is mass and k is stiffness. Here m is a stronger function being the in the denominator of a square root. So you can see that as “m” gets smaller, the resonant frequency “f” gets much bigger.

The use of an aluminum shaft provides a dual purpose – increasing critical speed out of the operating range AND directly reduces the rotational forces since those rotational forces are governed by:

F = mr w**2
Where w is rotation speed, m is the mass and r is the radius at which it is spinning.

This means that a 50% reduction in rotational mass results in 50% less rotational force. So, when a driveshaft rotates out of true, due to run out of the shaft itself or due to trans output shaft or axle companion flange run out, the reduced mass * the radius of gyration (i.e., run out) product is smaller than for the same conditions with a steel shaft.

This becomes important not only at critical speed, but at more normal operational speeds where the effects of run out and mass imbalance are more evident than those of resonance:

For a typical Fox or SN95 Mustang, driveline critical speed is around 95-100 Hz. Using stock tires we have the following:

225-60R15, 225-55R16, 245-45R17 all rotate at 812-820 revs/mile at 60 mph.

This give is 13.5 Hz wheel frequency at 60 mph, and assuming a 3.27 axle, we then have:

812/60*3.27 or 44.25 Hz , driveline frequency.

So, 100/44.25*60 yields a driveline critical VEHICLE speed of 135 mph. A good rule of thumb states that the objectionable driveline forces will start becoming significant at 70% of resonant frequency, so for the case of the 3.27 axle, the boom and vibration may be felt beginning at 95 mph.

Typically, 3.27 axles don’t provide the driver with much to complain about; it is 3.73 and above which create the concerns. Using a 3.73, we find that

13.53*3.73 gives 50.5 Hz wheel frequency at 60 mph (substantially higher than the 3.27)

And the critical VEHICLE speed then becomes

100/50.5*60 or 119 mph.

Taking 70% of 119 mph equals 83 mph, certainly a speed at which some Mustang drivers experience occasionally.

For a 4.10 axle, the “70% speed” is 76 mph!

Compounding this problem are factors like transmission output shaft run out, imbalances and run outs from components such as the reverse sun gear, driveshaft, companion flange and pinion pitch line run out (a torque induced run out created when the pinion tries to crawl up the face of the ring gear involutes).

Combine these factors and the already marginal NVH resulting from proximity to 1st bending (critical speed) and the NVH becomes absolutely agricultural.

The aluminum shaft minimizes the contribution from companion flange run out and the driveshaft’s own run out, directly due the lower mass. The pinion is free to pitch +/- 20 degrees and adding in any run outs of the companion flange or driveshaft at the pinion end results in the driveshaft mass having a large eccentric path to wobble about. It is this path times the mass of the driveshaft, which gives the characteristic boom and vibration at highway speeds.

Thus, as Newton predicted, as mass decreases so will the forces. That is why an aluminum shaft is your friend when coupled to 3.73s.

One side note: that great big mass on your pinion nose, fondly named by driveline engineers after the appendage on a male moose, is tuned to 45 Hz, the frequency at which the 2nd order forces created by u-joints as they rotate, force the pinion to bounce or pitch up and down and shake you by the seat of your pants and create an uncomfortable boom in the car. Once again run outs and imbalances will modulate this 2nd order driveline phenomenon to make it worse, so the moral is, LEAVE THE MOOSEB-, uh, DAMPER ON the pinion nose!

Another item: you CAN expect more axle noise when using an aluminum shaft however, which does not necessarily mean the pinion depth or side shims are incorrect, or that the gear cutting process is flawed. It just means that the aluminum shaft is more willing to “bend” circumferentially, torsionally and in a double hump (2nd bending) much more easily than a steel shaft.

Recall my prior statements at the very beginning about aluminum stiffness vs. steel? Picture a piece of sheet metal ducting. Bend it and it makes a WA-WA sound. That is pretty much what a driveshaft does, but at a much higher frequency – higher than even the dreaded “critical speed” of 100 Hz.

Axle noise will occur from about 350 Hz all the way through 500 Hz, sometimes even higher than that. The energy comes from the teeth meshing at the pinion/ring gear interface. This energy is transmitted to the driveshaft (and suspension components) and makes them deflect in the same sense as a piece of sheet metal goes WA-WA. Aluminum is less stiff than steel and takes less energy to deflect it, so it is far more inclined to make your axle go WOOOOO as you drive down the road at 45-70 mph.

Assuming again a 3.73 axle ratio, which has 11 teeth on the pinion and 41 on the ring gear, the axle noise frequency is calculated as (at 45-70 mph):

815/60*3.73*11 or 557 Hz at 60 mph.

This means the WOOO you hear at 45 mph is about 418 Hz and the WEEEEEE you hear at 70 mph is way up there at 650 Hz. You can’t SEE the driveshaft is bending and breathing and twisting, but it is telling you that precisely that is occurring.

So, now armed with this information, you now understand the basics of your vehicle’s driveline.

[CRUZTAKER]

The old part number for a 'Metal Matrix Comp PI' driveshaft is XW7Z-4602-AA and it has the inscription 'MMC POLICE'.....and yes, it comes with everything except the wrench to put it in.

I have one in my barn,it came 2 days ago, $185 delivered. No pics are needed, it's that clear. Just call someone, ask for the part, and ask them to verify the inscription.

As far as all this technical jargon, I don't get it. But I do get the simple law of physics....the drive shaft turns as fast as the the engine crank is turning it no matter WHAT gears are BEHIND the drive shaft.

And BTW, old members, if you consider just shy of 2 years an old member....there are newbies here everyday. They will bring up old topics now and then. We should respect that, and not offer them 'awards', but advice.

[Dennis Reinhart]

Well Barry I never meant to rain on your parade, I just like to deal in facts, and this subject has been covered over and over again, every one has there opinion, I respect yours, I have The Dynotech on my car as well as my Mark 8 you do as you like, all I was trying to do is show the facts and the reasoning behind the MMDS, again the CV PI shaft is not the same as the Dynotech and Ford States the PI CV shall not go beyond 128 MPH, with stock gears, and one of those reasons is the drive shaft, so if you are using a PI CV shaft with 4:10's you are exceeding that shafts design limits, ask Zack what happened to his car, and again I meant no disrespect and I sure never meant to be argumentative, all I have ever done is try help with this car.

[joflewbyu2]

I noticed the difference in the end pieces that connect the driveshaft as well as the size of the yokes too. where the stock shaft has 2 welds on each end the Dynotech only has one and also has larger yokes. I noticed a smoother driveline with a slight whirl at 45-50 mph that either I got use to the noise or it disappeared as I don't hear it anymore. CRUZTAKER, pics would be nice.

[CRUZTAKER]

OK, but I am not as fast as others in aquiring and posting pics. I'm not digital yet. I'll try to post by saturday...a little closer to the threads aniversary. :P

[SergntMac]

Awe come on guys...This thread is just a few hours away from making history! The opening post is dated 12-19-02, 1:10 PM. Surely we can s t r e t c h this until then, eh?

Just think of it, a whole y e a r in deliberation...T h r e e h u n d r e d s i x t y f i v e days of no one listening to each other, or, believing in simple truth. Good Lord, I l o v e it, it's so webby donchano.

This thread exemplifies exactly what goes on over the internet and now this site is contaminated too. Nervous Nellies...

No one posts here to learn anything new, no way. It just looks that way for a while when a new member asks a few elementary questions about gears, tranny, brakes, what ever. Y'all post your answers only to reinforce your own insecurity, and when y'all don't make that score, y'all just go have a beer. "Cheers!"

A world of experts could post a thousand correct replies a hundred times each, yet the only replies y'all pay ANY attention to at all, are the posts from those who show you that they know less than you know, because the playground is safe. Safe for the Marauder dot net version of the "paper tiger."

To look at it another way, you are less insecure than them, thus automatically King of their Insecurity Hill, which is just another form of pizzing match, only measured by turning negative feedback into positive scores. "Yeah, I'm reserving my judgement on this mod until I know more, but hey lookie here at Joe new guy, he's damn near shaking in his boots with indecision, poor guy..."

Come on now, I want to see this here thread run right over the opening post, just to see what happens. Work with me on this, we'll all learn something.

The bottom line here is simple, and thanks to a new member, we get to see this all played out first hand.

For you insecure dudes, here's your bottom line.

The OEM Marauder drive shaft is perfect for the car, from any angle you measure it. You'll drive this shaft into the sunset with full peace of mind, not a problem. Once you diddle with your MM and the OEM design, you need to consider alternatives.

If you feel any vibration, your alternative is the DynoTech drive shaft. Yes, there is only one alternative. Nothng else will do, there are no substitutes, no shortcuts, nothing cheaper, for you penny pinchers. Why?

Because, if you do diddle with your OEM Marauder, you're not going to stop diddling at Stage I. Stage I means first step, there will be more steps to follow, and most likely you will take them.

After all, this is the home of the 2 Percenters, where we blow it all out our azz to the max. Therefore, this CV/PI drive shaft, in any form and from any year, is just a temporary substitute.

You'll be buying another drive shaft anyway, may as well buy the correct drive shaft now and save yourself the time, coin, and worry over it.

One year ago, everyone here was N/A, and jumping for joy over breaking 270 RWHP. Howevr, there was one, and I mean ONLY ONE Marauder, that put 400+ HP to the ground. Yes, ONE, read the history here in this thread.

On 12-19-2002 at 1:10 PM, only ONE Marauder in the world could test the limits of the OEM drive shaft, and come back to debate that to it's full extreme, because only ONE Marauder could put 400+ HP through it. That Marauder was Bill (mensrea) Karrow's Kenny Brown built Marauder. The#1x. It's still driving on the DynoTech drive shaft today.

A wise man once told me that if I ignored my history, I was doomed to repeat it. So, tell me how this thread is any different?

Now look at us today...Any strike that...EVERY Marauder in the world, can put 400+ HP to the ground in one afternoon's work.

Any...I mean every Marauder in the world could put 700+ HP to the ground, with 24 hours of shop time.

We can do all that today, yet we are still debating which drive shaft is the best drive shaft, when only ONE drive shaft has done any of it, which it HAS been doing all along this past year.

Y'all deaf or sumptin?

Call Dennis, order your DynoTech drive shaft.

Or, shut the ****** up.




Sorry, Logan, I know you're gonna whup me for that, but there is only one way to make this point, and the truth must prevail.




Be safe, y'all, happy holidays.

[greyghost]

Uh, Sarge, could ya quit beaten around the bush and be a bit more direct? :-) I love this list. Everybodys like family!!

[Mikeenh]

For all you "NEWBIES", spend your bucks wisely. A year ago I thought a PI driveshaft was the way to go because Mensrea, the original owner of Sarge's MM had one on it. In September I bought a Dyno-Tech shaft from Reinhart to replace my PI shaft. I now have my original shaft and the PI shaft laying in my garage.
All the info is out there like Sarge said. Go first class the FIRST time. That's what Dennis deals in.....FIRST CLASS !!! http://smilies.sofrayt.com/%5E/_950/ole.gif

[jspradii]

Well said Sarge......well said.

[vegasmarauder]

I will my .02 worth. I got the MMC Police shaft to replace the MM shaft before the dynotech was avail. If you are keeping your MM stock but running at the speed limiter than the MMC is good. If you are going to take off the speed limiter or other mods, the Dynotech is the only way to go. The real MMC Police shaft was discontinued a year ago. The old part number if it is actually on the box will be the old MMC shaft. These are limited to existinf stock, they are not being made any more. Any new ones sent under the old part number are the new non MMC aluminum PI shafts. I know because I ordered one under the old number to see what came in and the new one is it. The smart money is go with the DynoTech and don't have any worries. If you can get an MMC for FREE, use it until you can afford the DynoTech.

[RCSignals]

That's right vegasmarauder, about the CVPI MMX drive shaft.
The reason they used a MMX driveshaft in the first place was They went to 3.55:1 gears for a few years. I think they also increased the speed limiter then.
For 2004, Ford has reintroduced 3.55:1 gears as an option for CVPIs. With that they may have also reintroduced a MMX driveshaft for 3.55:1 equipped cars. This is the question about that new part number.

[RCSignals]

Originally posted by SergntMac
Awe come on guys...This thread is just a few hours away from making history! The opening post is dated 12-19-02, 1:10 PM. Surely we can s t r e t c h this until then, eh?



Working on it Mac. It's made it in the big windy, but not here yet.

It'll go over, then this thread will never die :)

[CRUZTAKER]

Well, I'll be at work at 2:10pm est today....hopefully Mikeenh
will be around for the aniversary of his thread, and perhaps post the closing comments.

To all newbies, listen to Dennis and Mac and the others. They know what they are talking about. There are no long term alternatives if you're gonna kick it hard.

I'm done.
:up:

[billwork]

Ok attached are photos of the driveshaft. I am not sure how to tell if it's an MMX one? I take it the weld means something.

You guys tell me.

http://photostore.automark.net/dealerphotos/1380/4w7z4602aa%20001.jpg
http://photostore.automark.net/dealerphotos/1380/4w7z4602aa%20002.jpg
http://photostore.automark.net/dealerphotos/1380/4w7z4602aa%20003.jpg
http://photostore.automark.net/dealerphotos/1380/4w7z4602aa%20004.jpg

[kurly]

Dennis's DYNOTECH!

[joflewbyu2]

looks like stock shaft seen here http://www.mercurymarauder.net/images/reviews/driveshaft/IMAG0042.JPG

[joflewbyu2]

Here's the real deal http://www.mercurymarauder.net/images/reviews/driveshaft/IMAG0038.JPG

[mensrea]

drive shaft, what drive shaft?

[martyo]

Originally posted by mensrea
drive shaft, what drive shaft?

Who woke the sleeping giant???

[bozobill]

Hats off to you Bill K. You went where no man had ventured and set the bar WAY high for all of us. We should call you Columbus. I still have the video of the first burnouts in Indy. Unbelievable! Happy Holidays!

Bill

[joflewbyu2]

carfixer, did you get the driveshaft yet? was it different than OEM that came with the MM?

[CRUZTAKER]

I don't know if carfixer got his, but I've got mine, and yes it IS different. It also has the markings "MMC-POLICE". Mine does not look like the one Billwork posted, his pics do not show the identifying mark..."MMC-POLICE". Mine also has the very same color bands as the MMC shaft from Dynotec Motorsports available through Dennis. After all, they are both manufactured by the SAME company....DYNOTECH MOTORSPRTS!

[joflewbyu2]

cruztaker, are you sure ithe mmc-police driveshaft is made by dynotech? my dynotech had no markings. now the oem shafts have 3 color band markings.

[joflewbyu2]

cruztaker, can you post pics, please.

[CRUZTAKER]

Originally posted by joflewbyu2@aol.
...are you sure ithe mmc-police driveshaft is made by dynotech

It is my understanding that MMC is a trademark name from ITW Balance Engineering / Dynotech engineering services....

Visit their website=HERE (http://www.dynotecheng.com/customshaft.html)

And yes, tomorrow I will take pics and post them in the evening.

Don't forget that I am not condoning this product in anyway. Buy the high performance version thru Dennis if you are gonna be hard on your car.

[CRUZTAKER]

Pics as promised:
http://www.mercurygallery.net/mmnet/watermark.php?file=501/627Driveshaft_MMC_full-med.jpg

[CRUZTAKER]

Markings on shaft as shown:

http://www.mercurygallery.net/mmnet/watermark.php?file=501/627Driveshaft_MMC_logo.jpg

[joflewbyu2]

Thanks for the picks. Now we know what type of alloy is used (C291-T6). What are the numbers after the ones I mentioned? I'm Glad you got the improved driveshaft. I noticed there is no dampner on the shaft. The dynotech shaft end pieces are different. The mmc-police shaft looks like it uses the same OEM end pieces with different center shaft alloy composition. Kind of hard to explain but the people that replaced the shaft w/ Dynotech shaft probably noticed the difference while swapping the shafts by the clearence issues of the end pieces while using the extentions sockets.

[Bradley G]

Any feedback from someone who has tried the police driveshaft?

Bradley G

[vegasmarauder]

I got one of the remaining dealer inventory MMX ones a few days after I got my '03 300B. We have a 300a, and another 300B. I can tell the difference whe running at triple digit speeds. The MMX is smoother. It feels like less "tire" vibration. It was a good interim thing until the aftermarket MMX shafts came out, but I am happy with it. There are no more in dealer stock, and I don't think I would trust a used one.

[Wires]

Sorry to jump in here, but after reading all this, I'm still confused.

If I understood Dennis correctly, a stock driveshaft is good up to the max goverend speed of a stock car -about 120.

With 4.10 gears, that speed drops to about 100, (120 multiplied by 3.55/4.10) because with the new gears we get less distance per driveshaft revolution. That's how gearing AFTER the shaft affects us)

Now, even a car with a stock ECU program and 4.10 gears can exceed this speed. (but the speedometer will still say 120 something at the limit.) The problem gets worse with the limit removed.

So, with a stock driveshaft and 4.10 gears or more, we are running right past the set limit for driveshaft speed into the safety margin, and possibly past that.

My question is are my numbers correct? If I keep it in the double digits with my 4.10 gears, will I be OK untill I can comfortably afford the super-duper driveshaft that Dennis sells?

or

Should I squeeze somewhere and get one as soon as I can because even 100 is "too close." If getting the shaft keeps me from getting the shaft, (sorry, I just couldn't resist) I'll find a way.

Thanks for putting up with me.

[Dennis Reinhart]

What's that driveshaft rated at (speed-wise)?


128 mph,thats why the FHP and GSP use dynotech

[KillJoy]

You just replied to a thread that has been dead for 2.5 years, and quoted someone who has not logged in for 6 Months!

:up:

KillJoy

[CRUZTAKER]

Talk about a DEAD THREAD....:flamer:

These driveshafts aren't even available new any longer.
Long since discontinued.

I have one.

And I am not clear on DR's last post, but those vics using those POLICE shafts ran over 140 mph.
Hell, catch an old assed episode of 'COPS' from the 90's and you'll see video of PI's running 142 in pursuit.

Mine sure has, with NO vibrations some 30k into it's life on my MM with 4:10's.

[Dennis Reinhart]

You just replied to a thread that has been dead for 2.5 years, and quoted someone who has not logged in for 6 Months!

:up:

KillJoy


well thats the average of your dates Steve

[CRUZTAKER]

well thats the average of your dates Steve


His hand isn't offended. :lol:

[KillJoy]

well thats the average of your dates Steve


Uhhh......ok.

:shake:

KillJoy

[Blackened300a]

You just replied to a thread that has been dead for 2.5 years, and quoted someone who has not logged in for 6 Months!

:up:

KillJoy

:lol::lol:

He must be tying up all his loose ends.