95 transmission help

mine did that exact thing... to fix it i swapped in a 5 speed

NAH45212,

You have torque converter clutch shudder. Absolutely! You are describing the exact symtoms, particularly the part about it goes away when you step on the gas. You feel like you are going over a long row of those tiny little speed bumps, right, and it only happens at light to moderate throttle. As soon as you get on the gas harder, it stops.

Basically, the clutch surfaces on your stock lock up torque converter are shot. This is a known defect on all AOD-Es from 94 through 98. Ford published a TSB about it. But since it usually only happens after 60K or 70K miles, no warranty replacement! Only permanent cure is to replace your torque converter.

A short term fix is available from LubeGard (LubeGuard?). Very small tube of friction modifier that you add to your tranny fluid. It's called Dr. Tranny Instant Shudder Fixx (no lie, with two "x"s in fixx). It works for several thousand miles or so, but then the shudder eventually comes back. You can add another tube then, but in the long run a new torque converter is in your future.

I found a tranny shop that would sell me a tube, but most don't want to, since it loses business for them! You can buy it directly from LubeGard's web site. Just do a Google search.

Ben there, done exactly this, with my 95.

I agree with MLC Stang.
While its happening 'tap' the break pedal just a tiny bit. If the problem goes away, thats exactly what it is.

Had the same problem with my 94GT. Dr tranny's shudder fixx fixed my Aode for a few more thousand til it gave up for good, I bought it online but I saw it the other day in an O'Reilly's parts store if you have one of those.

So is the consensus that it's an issue with the TC (a hard part failure) or with running Mercon (instead of MV)?

HISSIN50 said:

So is the consensus that it's an issue with the TC (a hard part failure) or with running Mercon (instead of MV)?

Click to expand...

It's a hard part failure.

The problem as stated by Ford in the TSB is two-fold. The first cause is a breakdown of the friction properties of the older Mercon IV and earlier transmission fluid due to heat build up. The second cause is undersized friction plates in the torque converter clutch in the torque converters on all AOD-Es from 94 to 98. The combination of these two problems results in a grabbing-slipping, grabbing-slipping, etc. of the torque converter clutch during shifts at light to moderate throttle.

Ford now recommends Mercon V tranny fluid in all AOD-Es. The Dr. Tranny Instant Shudder Fixx is a friction modifier than can recondition the friction plate material IF it is not already too far gone. In most cases it is, and the Dr. Tranny stuff only works for a while.

MLC, thank you for the reply.

I always thought MV was more slippery than Mercon (lower coefficient of friction). If so, wouldnt the MV cause faster clutch failure?

What if someone were to use fresh Mercon (not MV) and keep the fluid egressing the trans (heading toward a cooler) under 170*F? That would assist in the two problem areas noted in the TSB, no?

I appreciate your time. I always see the same generic posts (often saying "Jerry said to do it, so we do it") and it's nice to hear from people who can actually think on their own and contemplate reasons things were said or done. We know MV is best, but I guess I always wondered if fresh Mercon is kept cool, how much worse is it than MV.

Thanks again for the info.

HISSIN50,

Actually, the way I read this TSB info is that the slippery stuff would make this problem worse. There needs to be a higher coefficient of friction between the friction plates in the torque converter clutch to make sure it grabs and does not slip during the shifts. And, I would think that the tranny fluid with the higher coefficient of friction would wear the friction material faster. However, I believe they are implying that the friction plate material technology has significantly advanced in the last ten years to the point that the stickier tranny fluid does not wear them as fast.

I forgot to mention that the Ford TSB also said to add an auxilliary tranny fluid cooler! So, yes, keeping the tranny fluid cool is very important to prevent this type of failure.

In fact, the TSB says to:

1. Replace the torque converter.
2. Flush and re-fill the tranny with Mercon V, and nothing else!
3. Install an auxilliary tranny fluid cooler.

I actually have this TSB somewhere in my stack of Mustang stuff at home, but can't find it right now. If I ever find it, I can't pdf the thing an post it somewhere.

I did all three things to my AOD-E when this happened and I've been fine for the past 25,000 miles. I actually had a local Ford dealer rebuilt my entire tranny when this happened. (The technician that did the work is known to be a really good tranny guy.) I also figured why not do a total rebuild as long as I have already paid to have the thing removed from the car! They gave me a limited warranty on the rebuild, but only if I kept nothing but Mercon V in it.

Thank you sir. I like to understand the logic/dynamic at hand with this stuff and you're helpin with that.

I wasn't totally sure if the solution was to make the fluid more slick so the clutches wouldn't catch, slip, catch, slip........... Or if the solution was to add so much more friction (going the other way - towards Type F fluid) that it bit hard at all times.
I must have been wrong in my interpretation that MV had a lower coefficient of friction than Mercon.



Oh, I thought I once read the TSB (back from circa 1997 IIRC) but didn't pay enough attention or didn't come away with *why* the retrofit of fluid helped. If I was a Tech I wouldn't care, but us enthusiasts like to know 'why we're doing this stuff.

I'm still not sure if: someone keeps Mercon cool and doesnt have any shudder issues, if it's best to convert to MV or leave well enough alone (I have read of some folks on TCCoA proactively swapping fluid and then having issues thereafter. That would lead to a big ).

Thank you again for the info.