Bill Ball

I thought it might last forever, but at 245K miles SOMETHING appears to be going wrong with my torque tube bearings. At least I hope that's all it is. It's not the usual failed bearing vibration and rattle. The other day I started to hear an odd, intermittent sound at idle. The noise is a metal-to-metal "clink" with some more low sounding grumbling/rattle. It's sporadic: clink, clunk, rumble, rumble, grumble....clink...rumble. It can be quiet for 20 seconds then start again. Coming from under the car.

So, I put the car up in the air and tried to locate the sound with a listening hose with the engine idling. I hear it about the same over the length of the drivetrain. Seems loudest over the torque converter, but that could be amplification.

I detached the flexplate from the flywheel and spun the TT shaft. It is making a steady rumbling noise. Not much play. Of course, the torque converter is spinning too. The torque converter cover bearings are new and the rear shaft clamp and flexplate bolts are tight.

I tried to replace the TT bearings last year just because I had the TT out to fix a torque converter seal leak, but the bearing carriers were stuck in their factory positions, at least in respone to a length of 3" PVC pipe and a 3lb sledge. Since the shaft seemed quiet, firm and had no significant play, I just left it alone.

Anyway, I'll pull the TT and see how it feels and responds to new bearings, even though the noise I am hearing is peculiar. My only concern is that after my recent tranny misadventure, this may be something more serious.

UPDATE:..... I unfastened the rear flexplate from the torque converter and pried the TC slightly away from it. Spinning the TT shaft manually, idependent of the TC and tranny - dead quiet and perfectly smooth. Not a good sign. It's now more likely to be something wrong with the TC or tranny. Maybe the primary pump, which was removed and resealed.

UPDATE 2: Maybe good news. I reinstalled the exhaust. Left the rear flexplate detached, attached front flexplate, so this just spins the TT - SAME NOISE. Now, I will detached the front flexplate again, so the TT as well all behind is isolated.

UPDATE 3: OK, I'm satisfied it IS the TT bearings. I detached the front flexplate from the flywheel and the noise while idling disappeared. I reattached the front flexplate to the flywheel with the rear flexplate still free from the TC, and the noise returned. On with the repair!

So, the good news is, it's pretty easy to isolate the TT from the rest of the drivetrain by unfastening the front flexplate and clamp and sliding it back away from the flywheel and detaching the rear flexplate from the TC and creating a little clearance there by slightly pushing the TC rearward. The TC floats a bit away from the primary pump, positioned by the rear flexpate. The rear flexplate cannot slide forward, so, you move the TC slightly back. This does not COMPLETELY isolate the TT, as the rear flexpalte still rotates with the TT shaft. So, any noise could be the TC cover bearings, but mine are newish. NOTE: Make sure the rear flexplate move very freely of the TC and does not drag the TC with it. Often the two are partially corroded together and running the engine with the flexplate bolts off could do some damage.

The noise is not "classic" bearing noise, so I felt I had to carefully isolate it, especially in light of the recent tranny work, but the noise is settling down to a more persistent, irregular rattle/grumble without any clinking and clunking.

See post #25 for findings....

UPDATE 4: I installed the damper with Rob's damper carriers, "pinned" both carriers with 2 small screws 180 degrees apart and put the TT back in the car. The drivetrain is quiet and the vibration at 3000 RPM (that was rattling the shift lever) is gone. The vibration and rattle was high frequency and If I left my hand resting on the shift lever, the car seemed fine otherwise. However, it seems a lot smoother over all now. Since the auto shift lever is not bolted to the TT, this vibration was being transmitted through the body as a buzziness, now gone. So, the damper DOES do something to very effectively control a somewhat subtle but annoying buzz.

Mike Frye

Hey Bill,

245k is a pretty good run. (I'm at 238 right now, with some serious mileage planned for the fall...)

Maybe disco the trans and slide it back first and spin it to isolate whether it's in the trans or TT? I think you'll have to do that anyway unless you plan to pull the TT and trans with the rear axles.

I'll be following this closely because I've no doubt that you're just a few steps farther down the path I'll soon be on...

James Bailey

Check to see if the cast iron balancer inside the tube has slide toward the trans. They can get loose and make clunking noises.

Dean_Fuller

Is it a clink, clunk, rumble, rumble, grumble....clink...rumble or more a clunk, rumble, rumble, clink, grumble....clink,...rumble. ?

I had to......I think I am in the same boat Bill....not looking forward to this one.

86'928S MeteorGrey

How hard did you go at the bearing with the 3lb. sledge? It might have helped cause premature failure... Except I wouldn't call 245k premature!

+1 on the vibration damper/balancer..

Bill Ball

I usually pull the TT by sliding the tranny back, dropping the bellhousing, unfastening the TT from the TC and pulling it out towards the front. Any testing on the car under idling conditions is going to be difficult. If the TT makes some noise off the car, then I'll be satisfied. I believe that to try to isolate the tranny as a source I would have to then remove the TC cover, reinstall the TT, but left disconnected from the TC, reinstall exhaust and start the car. That's a lot of work. Since the TT is original, if it rumbles off the car at all, I'll go with that. If that doesn't fix it, then the rear suspension and the tranny comes out and I may be calling 928Intl for a good used 89 auto. Oh, I would do some disassembly on the tranny to see if it might be something simple first.

UPDATE:...Skip what I just wrote above.. I unfastened the rear flexplate from the torque converter and pried the TC slightly away from it. Spinning the TT shaft manually, idependent of the TC and tranny - dead quiet and perfectly smooth. Not a good sign. It's now more likely to be something wrong with the TC or tranny. but...read on....

Bill Ball

Hi Jim:

I've not heard the classic "CLUNK" on acceleration and deceleration as that thing slides about. This noise appears when the car is idling.

Bill Ball

Exactly.

supercedar

Before I replace my TT I heard noises when shutting the engine off and starting it.. It seemed to be the noise you are hearing. I use to think it was the exhaust rattling but has since gone away with the Contantines.

Wish I was closer as I enjoy that job and would love to help!
Thomas

86'928S MeteorGrey

Cripes... Good luck with the transaxle...

Bill Ball

No that's not the time it makes the sound. It's quiet on start up and shutting off. Honestly, I have no solid idea what the sound source is. I already have the exhaust off. Now that I have the TC (and tranny) separated from the TT rear flexplate (the TC is pushed a bit into the tranny), I may reinstall the exhaust, reattach the TT to the flywheel and start the car. If there is no noise, that should nail it to the TC or tranny. Damn.

UPDATE 2: Maybe good news. I reinstalled the exhaust. Left the rear flexplate detached from the TC, attached front flexplate, so this just spins the TT. Started the engine - SAME NOISE. Now, I will detached the front flexplate again, so the TT as well all behind is isolated.

Bill Ball

OK, I'm satisfied it IS the TT bearings. I detached the front flexplate from the flywheel and the noise disappeared. I reattached the front flexplate to the flywheel with the rear flexplate still free from the TC, and the noise returned. On with the repair!

michael j wright

Bill, I wounder if this will also fix that elusive vibration that you have been hunting-let's hope.

86'928S MeteorGrey

Whew. I'm glad you don't have to dig into the tranny again. Good luck with the TT.

hb4

Bill,
I used an adaptation of Dwayne's allthread method to extract the bearings, using pipe fittings rather than the wooden plug. I think this is a 2-1/2" coupling with a 2-1/2" by 3/4" reducer. Might be 2-1/4", so should probably measure the ID of the TT and OD of the coupling. It was a pretty good fit. Here's some photos

Showing starting setup (after the fact, with previously removed bearing). Once I started to push the balancer, I added the PVC section.


Showing final extraction with PVC section to catch balancer and bearings


Showing the individual parts