4.10 Questions???

[03blackmerc]

im looking to put in some 4.10's in the MM. i see the ford racing set on Reinhart for $260. i know the MM has an 8.8 rear end so my first question is can you use mustang 4.10 gears?? i see a Ford racing set complete with installtion kit for $240 on late model resto. Are these the same gear sets?? My next question, do gears require a tune? shift points are obviously going to change. im not to savey on electric auto's so im not sure what will happen lol. any ideas?

[PSG]

your best bet is to get them right from ford, they should be right around the same price, and the motorsport gears are a good quality piece. and yes they are the same as a mustang 8.8. and yes you will need to at least change the speedometer calibration in the computer

[babbage]

Get the FRPP ring and pinon kit. You'll also need a dynotech driveshaft. (Reinhart) or find a used Alcoa MMC shaft -- 99 police car.

[fastblackmerc]

Get your gears from Ford Motorsports as mentioned along with new bearings and fluid. Will need to recalibrate your speedo with a turner as mentioned. Will not need a new driveshaft as long as you don't go into the 120+ mph range for any length of time.

[FordNut]

The gears will work, you will need a tune and most likely a good MMC driveshaft.

[Bradley G]

I had 4:10's in for 5 years and over 70K, no upgraded driveshaft yet.

[03blackmerc]

i have a chip an old x-cal from an 03 mustang gt, could that work? i dont have money for the drivehaft yet i will see what happens with the stock one for now

[rayjay]

The tune is necessary or your speedo will be way off and the tranny will not shift correctly. Your driveshaft may or maynot whip at high speed. I have not made many runs above 100 mph since mine were installed back in the spring. I understand you will know right away if its a problem once you maintain speed in that range. Until you can afford to buy a tuner, wait on installing the gears. The tuner's code must also matchup with your car's computer code or you could screw up your ECU if you did something irreversible. That will could cost you $800 extra to fix having to buy a new ECU.

[fastblackmerc]

I had 4:10's in for 5 years and over 70K, no upgraded driveshaft yet.

Same here, but I don't spend much time at very high speeds either.

[Blackened300a]

I had 4:10's in for 5 years and over 70K, no upgraded driveshaft yet.


Same here, but I don't spend much time at very high speeds either.

Same here and I topped 130mph with zero vibrations. Our new vendor, Sparta performance is offering the 4.10 gears for $160 and sells the install kits as well.

http://www.mercurymarauder.net/forums/showthread.php?t=57626&highlight=holiday+specials

[FordNut]

i have a chip an old x-cal from an 03 mustang gt, could that work? i dont have money for the drivehaft yet i will see what happens with the stock one for now

Probably will, just needs a different program loaded.

[03blackmerc]

Probably will, just needs a different program loaded.

I only bought the x-cal for 75 bucks, but i was told it is compatable with the MM. if that could do the trick ill use it. really dont want to spend $800 bucks putting in gears. the SCT's are expensive. as for the driveshaft maybe ill just buy the saftey loop lol.

[MrBluGruv]

you may end up hitting that mark after install anyways. Parts and labor when I priced everything out was about $800, but that's the gear set, all the install parts, a trak-lok rebuild kit which you'll probably want to do if you have any serious amount of miles on the car, and labor on putting them in.

If you avoid the last two steps by say not rebuilding and putting them in yourself though, you'll cut your cost in half easily.

[mrjones]

I did gears first, and went for a while before I got the tune. If I'd bought the tune first, I doubt that I would've done the gears at all. My suggestion is to get the tune and go from there. If you add the gears later, the tune can easily be updated.

[RF Overlord]

as for the driveshaft maybe ill just buy the saftey loop lol.That isn't the point. The D/S won't fall out when used with 4.10s, but if you run close to critical speed too much, the shaft starts to whip and flex and will destroy the tailshaft bushing & seal, then you get a big leak. If you continue this way, then you might have a catastrophic failure, but you'd know you were in trouble long before that.

[Stranger in the Black Sedan]

Our d/s is so long it should have been a 2 piece with a support bearing from the factory...like a delivery truck. The critical speeds of each smaller shaft would have been way high enough then.

[MrBluGruv]

...you might have a catastrophic failure, but you'd know you were in trouble long before that.


that's what has always been bothering me about hearing the driveshaft has to change, a lot of people here would have you think that out of nowhere the driveshaft will simultaneously fall out and shatter into a million pieces by even getting close to critical speed, and that it's the driveshaft that is the failure point.

Wouldn't it make sense that the most practical approach to minimizing this problem is to balance the driveshaft you already have?

[Stranger in the Black Sedan]

Balancing always makes people feel better, but do you really think the local d/s shop has a better quality machine, and calibrates it more frequently than Ford did? The factory paid a LOT of attention to minimizing NVH. The factory balanced shaft was even indexed to the trans and the rear yoke in a certain way, that is above and beyond what you are going to be able to achieve once you mess w/ the shaft balance.

[MrBluGruv]

what bothers me about that though is that with that information in hand, why is there such a broad range tolerance when it comes to driveline failure like that?

It just puzzles me how someone could blow the tailshaft at 120 on a dyno run, then another person could run for minutes at a time at a higher speed or one closer to critical speed and have no realistic damage.

I understand that at some point you'll reach a limit to balance due to the fact of how much the shaft weighs because of it's composition, but is it really that bad that if well-balanced it stil has a considerably high risk of failure at high speed on matter what?

[03blackmerc]

my buddy has his own shop we did the gears on my mustang and it came out great no problems. i have alomost 200,000 on the mustang now and i did not rebuild the trac lok and she rips two stripes down the road everytime. im not worried about the rear end or the driveshaft just if i got ripped off on the x-cal. i priced the ford racing 4.10 with installion kit even the oil for $240.00. im paying nothing for labor and i have the x-cal in my hand. now i guess i just wanna kno if the x-cal will be suffcient for the required 4.10 tune?

[fastblackmerc]

my buddy has his own shop we did the gears on my mustang and it came out great no problems. i have alomost 200,000 on the mustang now and i did not rebuild the trac lok and she rips two stripes down the road everytime. im not worried about the rear end or the driveshaft just if i got ripped off on the x-cal. i priced the ford racing 4.10 with installion kit even the oil for $240.00. im paying nothing for labor and i have the x-cal in my hand. now i guess i just wanna kno if the x-cal will be suffcient for the required 4.10 tune?

You have to get a specific tune for your Marauder. Then, if the tuner left the file unlocked, you can adjust the parameters or just get the tuner to make 4.10 tune.

[FordNut]

I only bought the x-cal for 75 bucks, but i was told it is compatable with the MM. if that could do the trick ill use it. really dont want to spend $800 bucks putting in gears. the SCT's are expensive. as for the driveshaft maybe ill just buy the saftey loop lol.

If it is unlocked, you'll just need to get a tune from somebody. Either a vendor, tuner, or Zack. If it is locked, you may have to send it back to to SCT and pay them to unlock it.

The driveshaft may or may not be ok with 4.10's, but many times I've warned people on here to expect to have to get a driveshaft along with 4.10's. Lots of times they don't believe me and a month or 2 later I see a post about a blown tailshaft seal, vibratiopns, leaking trans fluid, or broken tailshaft housing. Take your chances.

[LANDY]

The driveshaft may or may not be ok with 4.10's, but many times I've warned people on here to expect to have to get a driveshaft along with 4.10's. Lots of times they don't believe me and a month or 2 later I see a post about a blown tailshaft seal, vibratiopns, leaking trans fluid, or broken tailshaft housing. Take your chances.
fully agree.
i was one of the ones that broke the tailshaft.
not pretty

[scruff]

how fast were you going when she cut loose?

[scruff]

i,ve had my p71 going 140mph with the stock shaft no vibrations at all smooth as silk,,but i,m going to be installing a new set of 3.73 soon and i will put the stock shaft back in and see what happens? i also have a MMX shaft out of a 99 p71 if i run into problems

[LANDY]

how fast were you going when she cut loose?vibration started @ 110mph, then i kept going till 120mph, (kinda Wreckless i know) then saw smoke on my rear view mirror. that was it
keep in mind this was in 3rd gear o/d off

[GreekGod]

Balancing always makes people feel better, but do you really think the local d/s shop has a better quality machine, and calibrates it more frequently than Ford did? The factory paid a LOT of attention to minimizing NVH. The factory balanced shaft was even indexed to the trans and the rear yoke in a certain way, that is above and beyond what you are going to be able to achieve once you mess w/ the shaft balance.

This is far more than a simple balance problem, especially on our MM's. There are many factors that go into a proper driveshaft. Stiffness, whip, resonant frequency, and driveshaft speed (related to rear end ratio) are just a few. I believe Reinhart or someone else posted a long tech article on the many problems involved.

-----------------------

[Mr. Man]

Anyone ever try a carbon fiber shaft?

[FordNut]

Yes, I believe Joe Walsh has one.

[Stranger in the Black Sedan]

This is far more than a simple balance problem, especially on our MM's. There are many factors that go into a proper driveshaft. Stiffness, whip, resonant frequency, and driveshaft speed (related to rear end ratio) are just a few. I believe Reinhart or someone else posted a long tech article on the many problems involved.

We know dude, we know. Hence the more exotic materials used for the MMX and other composite shafts. I was commenting on balancing only. I have had local yokel balance jobs done and if you ask the guys, what rpm are you gonna balance at? Most don't know. Also ask, when is the last time your machine was calibrated? Most don't know. So a re-balance at some random driveline shop may not actually be an improvement over stock. I see some driveline shops on the net that will tell you, we balance at 6500 rpms using a this-and that state of the art fancy machine, and that is the kind of shop you need to find.

[RF Overlord]

Wouldn't it make sense that the most practical approach to minimizing this problem is to balance the driveshaft you already have?The problem has nothing (or very little) to do with balance...it has everything to do with resonance. The driveshaft is so long it becomes like a jump-rope above a certain rotational speed, called Driveline Critical Speed. I'll try to find the link to Dennis's article. The nub of the problem is that you can balance your existing driveshaft to a million RPM and it will STILL go hoopy above DCS.

[MrBluGruv]

Yeh, the crazy vibrations are happening in a different manner than I had first thought. I'm thinking I may just save the money up for forced induction instead then and be done with it. :( By the time I can afford forced induction anyways, 4.10 may not be the best ratio.

[FordNut]

4.10's aren't the only way to experience the problem. Remove the speed limiter in the tune and run it fast enough, you may reach the critical speed even with the 3.55's

[babbage]

The problem has nothing (or very little) to do with balance...it has everything to do with resonance. The driveshaft is so long it becomes like a jump-rope above a certain rotational speed, called Driveline Critical Speed. I'll try to find the link to Dennis's article. The nub of the problem is that you can balance your existing driveshaft to a million RPM and it will STILL go hoopy above DCS.

Click the link in my sig that says Alcoa driveshaft. Info is there.



Originally Posted by babbage http://www.mercurymarauder.net/forums/images/buttons/viewpost.gif (http://www.mercurymarauder.net/forums/showthread.php?p=781192#post78 1192)
MMC = Metal Matrix Composite. The Composite is a special blend of Aluminum and Steel that Alcoa manufactured into driveshafts for Ford PI's in 99 and 1/2 of 2000. The MMX shaft made by Alcoa was a BLEND of metals which was 30% STRONGER than aluminum, yet it weighed the same as an all aluminum shaft. This is why those AMMX shafts are so sought after -- this is what I remember from my research about this.

MMC police shaft is about 1/4 lb lighter than the aluminum police shaft, and a few pounds lighter than the longer aluminum shaft. MMC is only slightly lighter than 6061 aluminum. Mild steel is about twice as heavy as the MMC.

My MMC feels feather light, especially after I removed the steel yolk and universals, it's only about 6 lbs.

MMC's elasticity is nearly 1.5 times that of 6061 aluminum, this allows the MMC shaft to absorb more drive-line vibrations. The issue with shafts is that they create ultra high frequency vibrations at high rpms, and they will eventually self-destruct. It also absorbs shaft "twist" much better.

The 53" police MMC shaft's critical speed is 9093 rpm, and the aluminum shaft is 7930 rpms.

I have no idea about the high speed extended run testing of the MMC? It will out run 6061 aluminum in every aspect, and is the best alternative aside from carbon fiber for our cars. Carbon fiber is as good an improvement over the MMC as the MMC is over the 6061, and it brings the rpms up to about 12-13000 rpms at critical speed.

Note: critical speed is a max, if you reach it, your shaft can become a deadly projectile.

For those who would like to tell whether a driveshaft is MMC or not:

MMC - found on most (not all) 1999 and 2000 P71's - has pink and green stripes running around the shaft, and if you look carefully in small black print you will see the letters "MMC"

Aluminum - on all other P71's - markings vary by year but 1999/2000 ones have pink/blue/orange stripes

Just a note on MMC: The modulus of elasticity is 14.1 million pounds per inch2. The density is .106 pounds an inch3. Aluminum elasticity is 10 million pounds/inch2 and .098 density.

:D

maximum Critical Speed (16 inch wheels)
--------------------------------------
CVPI Amuminum Driveshaft 4.10 = 116mph
CVPI Amuminum Driveshaft 3.55 = 132mph
CVPI Amuminum Driveshaft 3.27 = 145mph
CVPI Amuminum Driveshaft 3.08 = 154mph
CVPI Metal/Matrix Driveshaft 4.10 = 133mph
CVPI Metal/Matrix Driveshaft 3.55 = 154mph
CVPI Metal/Matrix Driveshaft 3.27 = 167mph
CVPI Metal/Matrix Driveshaft 3.08 = 177mph

[MrBluGruv]

4.10's aren't the only way to experience the problem. Remove the speed limiter in the tune and run it fast enough, you may reach the critical speed even with the 3.55's


I've definately gone well into that territory already with no noticable negative effects, no vibrations no drag no nothing, but not in a long time though. Honestly, even if I get 4.10s, I don't see myself going past 120 much if at all. I enjoy high-speed running, but it's proven time and again that this car isn't going to get my exactly what I want with that, so I figure if I can get a damn quick 0-80 or 90 I'll be very satisfied. You think if I speed limited myself to like 120 to forcefully remove the temptation I would dramatically reduce my odds of having the tailshaft fail on me?

[fastblackmerc]

I've definately gone well into that territory already with no noticable negative effects, no vibrations no drag no nothing, but not in a long time though. Honestly, even if I get 4.10s, I don't see myself going past 120 much if at all. I enjoy high-speed running, but it's proven time and again that this car isn't going to get my exactly what I want with that, so I figure if I can get a damn quick 0-80 or 90 I'll be very satisfied. You think if I speed limited myself to like 120 to forcefully remove the temptation I would dramatically reduce my odds of having the tailshaft fail on me?

I think it would depend on how long you stay at 120.

[MrBluGruv]

lol, true. Whenever I manage to get into that range, I don't stay very long. Past are the days of cruising 110mph+, at least in this car. I guess I really shouldn't panic so much about stuff so easily.

[MrBluGruv]

Couple questions came to my mind today about this, haven't seen them specifically addressed much if at all:

1. if the critical speed of an aluminum driveshaft is 116 for 4.10 rear gear and a 16" wheel, would that make it 130.5 for an 18" wheel? (figure divide 116 by 16 then multiply that by 18 for adjusted mph.) I am well aware I could be wrong on this, math is SEVERLY not a strong point of mine.

2. When going to a steeper ratio for the rear gears, I understand that the critical speed drops, but does the intensity of vibrational force also increase at the new critical speed over the old critical speed? e.g. (random numbers here) 10lbs outward for 3.55, 15lbs outward for 4.10?

Pretty sure the answer to these would seal the deal for me on whether or not to do this right now and at least plan on buying a new driveshaft later.

[babbage]

If you use the circumference of the tires (89.9) for 18" wheels it comes out closer to 120. (124.59) This should be the "explode" number (Maximum safe theoritical). Before you hit that however you have should have vibration and possible tailshaft damage. Some people are fine others are not --so there is some margin of error/inconsistency with this data. Could be as high as +/- 10%

My opinion: better and safer to get a 99 P71 DS or a nice new Dynatech DS from Reinhart if you go with 4.10's

[GreekGod]

Drive line Critical speed
What it is –
Every rotating object has a “critical” speed or resonant speed, which is a function of its design, mass and stiffness (http://www.mercurymarauder.net/forums/showthread.php?t=5163&highlight=metal+matrix+drive+s haft#). 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 (http://www.mercurymarauder.net/forums/showthread.php?t=5163&highlight=metal+matrix+drive+s haft#) 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.
Eureka (From Dennis Reinhart):


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.

[babbage]

Deja Vu

http://www.mercurymarauder.net/forums/showthread.php?p=796482

[Mr. Man]

What kind of shaft do NASCAR cars use? I know the cars are smaller but in the good old days they raced big cars and I don't know if carbon fiber was available.

[bawazir]

any after market Drive shaft that i could buy?
i am doing my 4.10 this week so i was thinking to do all those at ones

[SC Cheesehead]

any after market Drive shaft that i could buy?
i am doing my 4.10 this week so i was thinking to do all those at ones

http://www.dynotechengineering.com/home.htm

Available through:

http://www.reinhartperformance.com

You can also check out auto salvage yards for used CVPI driveshafts.

[Vortech347]

Search your local stang boards.

I picked up my 4.10's for $50.