Schocki

Rennlisters,
Sharky is back together and ready for battle. Everything went back into the car without any problems. Actually I had a lot of fun replacing the torque tube and the rear torque converter carrier bearings. The more I work on this car the more I admire the level of engineering and thought that went into this piece of machinery. The only thing that you need is time and patience.

Here is what I replaced:
- Rear crank seal
- Torque tube
- Torque converter bearings
- Torque converter seal
- O2 Sensor

Here is what I checked:
- Crank end play (0.3mm)
- Adjusted the flex plate to factory spec. 0.4mm gap towards flywheel
- Painted additional marking on torque tube shaft to be able to see shaft movement or flexplate movement.
- Flexplate is glued on shaft with Loctite 290

Took the car for a drive today and WOW! What a difference! The car is so much more quiet AND the rear end vibrations at higher speeds are completely gone. Took it out on the highway and drove it up to 100 Mph and the car is absolutely smooth. It is just like the motor mounts: You don't know what you're missing until you change those. If you have rear end vibrations at higher speeds and your tires are balanced, there is a good chance that your carrier bearings start to fail.

The play that I had in my rear carrier bearings was 0.4mm per bearing. I'm not sure if worn bearings could cause these vibrations???
Could the hydrodynamics in the torque converter be responsible???

Here is my post about the repairs with pictures https://rennlist.com/forums/928-forum/228734-failed-torque-converter-bearings-or-why-do-we-have-these-flex-plate-issues.html

borland

Good to hear.

Looking at your clutch housing bolt wrench setup on the other thread.....

I always wondered who would buy one of those Craftsman 3/4" breaker bars with such a short handle, well now I know.

and, it looks like it would be real easy to use a 3/4" socket adapter and torque wrench when tightening those bolts. That's one bolt you don't want to strip or find stuck later.

borland

Nicole

Coingratulations! This sounds like an all around success. Now you can drive again like these guys in the golf carts - just faster...

Thank you for your detailed ducumentation!

Schocki

I originally bought the wrench for the rear axle nuts that connect the CV joints to the rear wheel assembly. You can stand on the wrench and those nuts come loose with no problem at all.

Bill Ball

I found this old thread and it may be relevant to my car. I have had a undiagnosed high pitch driveline whine only in P or N for the last 3 or 4 years. Sounded more or less like a noisy fuel pump. Recently, I have developed a strange 80+MPH vibration that feels all the world like a rear wheel out of balance. BUT it's there with 3 different wheel sets and a careful balance. Axles are good, tranny mounts are new. Now, the old whine has changed. It's there sometimes in gear and the tone is lower.

So, I was thinking of dropping the TT and doing the torque converter as Schocki did. Wonder if that will cure my vibration as well as the whine? While I'm in there, I might as well do the TT bearings even though I have no indication they are bad yet despite 220K miles.

Schocki

Use a mechanics stethoscope to locate the faulty component first.

borland

Bill,

For the noise alone, you should have done that long ago.

Find a transmission jack so you can easily remove/reinstall the tranny. You'll find the job much easier done than fighting to move it back. Regardless, its not a big job, just some very heavy parts to deal with.

Bill Ball

Schocki: The noise can be heard all over the driveline. Hard to distinguish the source.

Borland: I've done them both ways. I'll probably do it with the rear suspension and tranny left in place, even though that presents its own obstacles. And I guess it was foolish to sit on this noise for so long and probably 50K miles. It just never changed until recently. We'll see what is inside the TC when I get in there.

Bill Ball

OK, beside the TC bearings, what else do I need when I get into the TC? I'm thinking 1,3,9(x2),10 from this PET page. And Stan, I won't forget to lube the bushing.

borland

Bill,

You won't likey need part '9'. Plus you don't know whether your leaking from '10' or '1' until you take it apart. More likely its '10' that's leaking.

You could always reseal the primary pump, reseal the piston for reverse gear, and check the clutch pack for reverse gear. But that's probably unnecessary work.

My 90' S4, I had a problem with reverse slipping when backing up a hill. Reverse would slip and also grab with too much throttle. That made backing up unsafe in some situations. I could have just fixed that problem from the front end, but instead I went with a complete teardown and reseal.

SeanR

I've not encountered 10 leaking, but 1 and one of the 9's I have. Any time I have the TT out those are the two I replace.

Bill Ball

OK, I'll order all those parts. I'll probably just do 1 and 3 unless there are other indications, although there are no external signs of a leak around the TC. Reverse is solid in my car.

Schocki

Hi Bill,

but if you have the car up on a lift with the engine running, you can pinpoint the noise with the stethoscope.
Did that on mine too, worked really well. Otherwise I would go with Sean's recommendation.

I replaced the TT with a rebuilt unit from Mark Anderson. Just to be sure that I have no future driveline problems.

Don't forget the O-Ring between tranny and differential.

Bill Ball

Schocki:

OK, I'll give it another listen with the stethoscope. Now that the noise seems more prominent, I may be able to locate it.

What's this about an o-ring between the tranny and diff? I hadn't planned on trying to separate them.

Mrmerlin

Bill i would suggest that you replace
PN 1 the TC radial seal
PN 3 the front pump O ring
Leave PN 10 alone, it will be stuck to the trans case and you will probably damage the sealing surface if you try to remove it just wipe it off with a clean rag
Also consider Seans suggestion.
i have resealed a few of these and 1 and 3 are the only seals i replace.

Also note if your getting a whine you might try to pick up a newer front pump thats where the 2 seals (1 and 3) go.
Put a smear of vaseline onto the bronze bushing behind the radial seal so the TC snout wont seize when the engine is started

Also consider replacing the vacumm modulator with the updated part and you should pull the trans to do this work