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Zack
08-17-2004, 07:45 PM
Well it seems as though Im making an annual event of burning up my transmission. I lost Overdrive at MV1 AND MV2, how ironic.
The first time the trans was rebuilt revealed every clutch pack, the overdrive band, snap rings, gaskets, etc were COOKED. So the trans was rebuilt to Jerry W. specs and off I went, thinking I had an indestructable transmission.
Well, MV2 comes along and bye bye overdrive. So I get the car home, (thank god for a 2 hour ride vs. 17 hours from Texas!) and pull the trans.
After disassembly, I find the overdrive band is fried, along with the reverse input drum (what the overdrive band 'clamps' to. This is also what happened the first time being rebuilt.) The intermediate clutches are also burned up 50%, which is very uncommon because they are so big. Everything else looks fine.
I can understand why overdrive went out, bad driving habits no doubt. I am notorious for going in and out of overdrive under a lot of power, which rapidly decreases the life of the OD band, on a S/C car or bone stock.
Easy fix, turn OD off around town, never do a WOT downshift out of OD (turn it off first, making sure it is disengaged before going WOT) and only use it when I know Im gonna be cruising around for extended periods.
So a new OD band and reverse input drum is on the list.

On to the Intermediate clutches. Im still confused about this, so I buy a dial caliper to measure the steels and frictions. Turns out when it was rebuilt last, this clutch pack was built on the highest side (loosest) of allowable clearances. Fine for a stock Marauder, but obviously not for mine. So I borrowed a special Ford tool for measuring the clearance and built this clutch pack to the low side (tightest) of tolerance. I was within .001 of the lowest measurement allowed. Im satisfied this will remedy the situation. I also raised the trans pressure a little with my SCT Software.

On to the torque converter.
Im gonna take advantage of Precision Industries 2 year 'free rebuild and stall speed change' I talked to Jack at precision and told him I wanted the Converter to be gone through, checked and the stall speed raised to 3500. No problem he says, just send it in. Folks, I sent it out Tuesday and I had it back the following Tuesday; unbelievable service. I paid 16 bucks for shipping. Obviously I want the stall speed changed to bring my 60 foot times down, which I will discuss later.

While I was in the trans, I replaced all the friction plates (which didnt need changing) but if you are a car guy or gal, you know why I did this, just because. All in all, parts total straight from the Ford Dealer totaled up to $200. Keep in mind the reverse input drum, which is not usually replaced unless you are a maniac driver like me costs $80 bucks by itself. I also picked up a Ford Racing Trans Pan which sells for $200. 2 extra quart capacity.

So I get it back in the car, which is considerably harder when you have Kooks Headers, but it went in without a hitch. I start it up after Midnight on a weekday, fill it with fluid and go for a ride. Its awesome for a mile until I downshift into second. Unfortunately, I only had second after this. Turns out the long electrical connector below the valve body came loose on one connection, no problem, reconnect it and its fine. I wont let this happen ever again!

Off to the track. the stall speed change is incredible for the track and the street. There are NO temperature increases and driveability is almost identical to the 3000 stall. Im pleased. The engine also revs much quicker.
After 4 runs at the track before it poured rain, the converter change netted me a 1.738 60 foot time; with my previous best of 1.83 @ 3000 stall. Not bad for free, huh? I ended up with a 12.092 et, awesome! When I get my electric water pump installed, 11's should be within my reach.

Back to the trans. Another reason I attribute my OD failing is because of constant manual shifting. When you are manual shifting from 1-2, the trans applies the OD band, which is bad. Im not sure if it remains unengaged when OD is off, but I will look into it. So this is a tech article and friendly warning to anyone here who drives like me. You WILL cook OD very easily.
Change your driving habits if anything here applies to you. Just put it in drive and forget about it. I used to have to manual shift when I first got into modding the car because it would hit the rev limiter if I did not have control of the trans manually. Now that I have the SCT Software, I can make changes on the fly. Would you believe my car shifts between 6500 and 6700 when im at the track. I go through the trap at 6600rpm. Scary isnt it? But it refuses to blow up, so Ill keep pushing it harder.

After the 3500 stall change, the shifts felt weak due to the looseness of the converter. So I went into the software and damn near maxed out the shifting pressure, which yielded tight, crisp shifts once again. It will probably aid in clutch life as well.
On a final note, this transmission is a breeze to rebuild. Do not be scared of it, a Turbo 400 is harder, Im not kidding.
Treat your transmission with the kindness it needs to stay in one piece, because Im sure not many of you enjoy rebuilding them, let alone removing them on a garage floor.
I hope you enjoyed this-
Zack

Slowpoke
08-17-2004, 07:52 PM
thanks for the info Zack. I am sure it will come in handy for many of us!

Bigdogjim
08-17-2004, 07:53 PM
Zack: Well written. One question do you use synthetic fluid in your transmission?

Do you feel it's worth it? Would it make any differance?
Thanks

FordNut
08-17-2004, 08:08 PM
When I had the DR Level II kit put in mine, the OEM OD band was burned up and the drum was scored. The Kevlar band that came with the kit should last longer (I hope). The Kevlar clutches that came in the kit were thicker than the OEM ones, so the only way they could set it up was on the tight side. Some of my parts were warrantied, but that probably won't be possible next time since the tranny is modified.

Zack
08-17-2004, 08:18 PM
Kevlar OD bands are frowned upon by many trans experts, Jerry W. and Lentech Transmissions included.
Fordnut, I have worked with the DR Trans kit and that band is NOT Kevlar.
You see Kevlar is damn near impossible to wear out, but has drawbacks.
Its potential to 'grab or apply' is less than that of stock friction plates.
If you use a Kevlar OD band, it will NEVER stop the Reverse input drum from spinning. It will turn less than 50rpm and wont take life off of the band, but the heat generated by this takes its toll on the whole transmission if not properly cooled.
As for fluid, I feel synthetic is too slippery for the Precision Converter.
I want it to lock up to its full potential. I change the fluid regularly and my trans temps with a 3500 stall and cooler never exceed 180. Around town and spirited driving will net 165 degrees, right where I want it.

GarageMahal
08-17-2004, 08:18 PM
Good read, thanks.

On the topic of transmissions... I have a long history of wearing out Ford trannys quickly and want to try to avoid it with the MM and appear to off to a good start with 32,000 miles on her so far.

So I know that heat is a big enemy and my question is what is the best way to drive to keep the heat down? My assumption is shifting is a major cause of heat generation but really don't know.

Considering most of my driving is done on the freeways in town I end up having to vary my speed between 50 and 75 quite alot. For the most part, I keep OD off unless I can maintain 65+ for an extended period. Is this good or bad for the tranny. One thing I have noticed is that I get better gas mileage driving like this than I did when I lugged from 60 up to 70 in 4th gear.

jta

jgc61sr2002
08-17-2004, 08:57 PM
I agree. Heat is the most importent factor in transmission failure. An additional trans. cooler couldn't hurt. JMO.

Constable
08-17-2004, 09:28 PM
I cooked the trans fluid already... DR kit has been in since 5-8-04. Don't see any issues w/ the PI 3000... hope it's not trans related. My trans temps NEVER go above 145. They usually hover around 130 or even a bit less.

Think the burnt fluid may be attributed to that OD band slipping?

teamrope
08-17-2004, 10:00 PM
Zack,

I remember you saying that you lost OD at MMville II. I'm glad to see that you got it fixed better than before, without breaking the bank. Congrats on the lowered 60" time, and looking forward to seeing you in the 11's.
:beer: :party:

(On a side note, I don't know why the IMOA didn't have you down for the brickyard, they have you listed in the member directory :( )

sailsmen
08-18-2004, 03:25 AM
Excellent article! :up:

Phenominal time! :awe:

How is your traction on the launch, are you using slicks or drag radials?

TripleTransAm
08-18-2004, 09:26 AM
Excellent read, Zack, and timely too... since your initial post on the subject, I've been hoping the topic would come up since I was sure you'd have good insight to share.

The problem with dropping out of overdrive: do you see this happening on a regular pedal-induced (ie. load-induced) downshift out of OD as well as the manually-induced ones? I too have the habit of occasionally popping the tranny out of overdrive for a quick highway move, when I want to avoid the explosive downshift that occurs when you have to depress the pedal some 80% before getting any decent acceleration at 55-ish mph.

By the same token, would you say the aftermarket programming available on chips / flashes can accelerate this wear based on the fact that the trannies are now downshifting out of overdrive more often on their own?
Also, for a while I was wondering, based on something posted by Lidio a while back, if there was something in the firmer shifts to OD that was accelerating the 'c-clip' issue due to the binding Lidio reported, and why he didn't firm-up the 3-4 upshift any. I wonder if these factors come into play with the situations you've seen.

Once again, thanks for the detailed info, and I eagerly await your insight on the above questions.

Smokie
08-18-2004, 09:41 AM
Zack, thank you very much for the excellent post, very helpful. I enjoyed reading it a great deal....and congratulations on your 12 at the track.:up:

Zack
08-19-2004, 03:09 PM
Excellent read, Zack, and timely too... since your initial post on the subject, I've been hoping the topic would come up since I was sure you'd have good insight to share.

The problem with dropping out of overdrive: do you see this happening on a regular pedal-induced (ie. load-induced) downshift out of OD as well as the manually-induced ones? I too have the habit of occasionally popping the tranny out of overdrive for a quick highway move, when I want to avoid the explosive downshift that occurs when you have to depress the pedal some 80% before getting any decent acceleration at 55-ish mph.

By the same token, would you say the aftermarket programming available on chips / flashes can accelerate this wear based on the fact that the trannies are now downshifting out of overdrive more often on their own?
Also, for a while I was wondering, based on something posted by Lidio a while back, if there was something in the firmer shifts to OD that was accelerating the 'c-clip' issue due to the binding Lidio reported, and why he didn't firm-up the 3-4 upshift any. I wonder if these factors come into play with the situations you've seen.

Once again, thanks for the detailed info, and I eagerly await your insight on the above questions.


Rather than go into detail here, Ill say a few things.
Since the spira-lock snap ring was installed last time around, it is still in perfect condition. As for OD, there is a huge spring that sits around the shaft of the servo. When doing a performance rebuild, the spring is swapped out with a lighter one, allowing the line pressure to provide a stonger clamping force on the band, which is excellent for acceleration in OD WITHOUT commanding a downshift.
Nothing can help the OD band when upshifting or downshifting under power. If you drive it rationally, you will have no problems.
Firming up the 3-4 shift through programming is good because it applies the band faster, reducing the chance for slippage and wear. Again, it does not matter while under extreme loads, the band WILL wear out prematurely.
Just keep overdrive off until you know you will be cruising for a while!

CRUZTAKER
08-19-2004, 09:51 PM
Just keep overdrive off until you know you will be cruising for a while!
Great summary, and as you know, I am no motorhead mechanic.....but I told ya so...he he...:whistle:

Glad it's under control and you have changed your ways. Great times as well!

3500 stall....mmmm

BillyGman
08-19-2004, 11:19 PM
Thanks for your post Zack. Hey, a 60' time of 1.7? That's excellent!!! Congrats. Ya know what's funny? How I shy away from transmission work, yet you dive right into it, yet at the same time, you shy away from swaping rear end gears yourself, while that's something that I dive right into. Too bad we don't live closer together in proximity. Otherwise, we probably would be learning a lot of car stuff from eachother. But I guess we still can learn some things by simply sharing on this board. Thanks again.

BTW, I've noticed that when I leave the O/D on, and I hammer down the gas pedal, it slams so hard into second gear that it actually feels pretty close to a neutral drop!!! However, when I hit the O/D button to shut off the O/D first, and then hammer down the throttle, it shifts super smooth, and yet still very tight. It's a perfect shift every time. I wish they could make an automatic transmission that would downshift like that regardless of whether or not you have the O/D on or off. But I guess that's asking a lot.

Anyway, I've noticed how harsh the downshift is while the O/D is on even before I S/Ced the car. So it obviously has nothing to do w/all the extra power created by the S/Cer.

TripleTransAm
08-20-2004, 08:03 AM
Nothing can help the OD band when upshifting or downshifting under power. If you drive it rationally, you will have no problems.


You mention 'extreme loads' but that's something I surely will NOT be experiencing anytime soon. ;)

What you said above (that I quoted) is exactly what I'm worried about: aftermarket tunes seem to promote easier out-of-OD downshifting, from what I gather. Even if I think I'm going to be cruising for a considerable while, there might be a situation where I'll ask for more engine power and wham, I'll get a downshift along with it. Right now with the stock programming, it takes a small thermonuclear detonation to get the tranny to downshift out of OD at highway speeds, but I'm worried about aftermarket programming.

Alas, now I'm stuck with two opposing views on the upshift-to-OD firmness... one tuner saying a firm shift promotes some binding resulting in tranny failure, another tuner saying firm upshifts to OD are better. I thought I read Jerry's material claiming the newer trannies had no trouble with OD downshifts as well... but this isn't the case after all? :confused:

Hope you don't take any offense at my probing questions, Zack... I value your input on the subject and I'm just trying to determine what the safest approach will be once I get my hands on the tuning software.

FordNut
08-21-2004, 02:21 PM
that band is NOT Kevlar.
Talked with my tranny builder today, he tells me both the clutch plates and the OD band ARE Kevlar.

Checked my fluid, it looks and smells like it just came out of the bottle.