Bill Ball

Having more fun. Got the bellhousing off, but I am finding dropping the front end of the TT below the flywheel edge so it can be pulled out (once the rear bolts are removed) is more problematic than on previous jobs. I have only done 90+ cars this way, with no serious problems, BUT in my case (89) the rear differential seems to be hitting the underside of body limiting the amount that the front can drop. Argh! I loosened the rear crossmember mounts, but it did not drop - probably need to jack up the rear. If I can just get it to drop an inch, that should do it, I hope.

Tails

Bill,
Stop giving your TT viagra and it may help.
Tails 1990 928S4 Auto

Garth S

Dumb question perhaps, but is the flywheel off? .... There's ~1.5" clearance to be had if it's still on.

Bill Ball

I've done this w/o removing the flywheel before, although on 90+. Was about to remove the flywheel when I gained enough clearance anyway and things went smooth from there. One 20" long 1/2 drive with a long breaker and the rear upper TT bolts gave with a nice snap. The TT seems perfect - shaft seems smooth and quiet and bearings are firm. Remarkable for 221K miles. Will replace anyway. TC shaft seems similarly solid and smooth too. Argh! I'm banking on the TC bearing being the fuel pump-like noise I hear in neutral and park, and I was hoping it might be causing a high speed vibration that is not traceable to anything else. Oh, well. The car deserves the service even if it didn't need it yet.

Bill Ball

OK, I got some time today to pull the TC. First I wanted to remove the TC cover, leaving the TC itself in-place for removal separately figuring that would allow more clearance and easier removal. I've removed TC covers this way before. But today the cover would not separate from the TC. I squirted PBlaster down the shaft, and after 45 minutes of various persuasion techniques, the cover came off, but it partially dragged the TC with it and I agitated the TC a lot, ruining any seal behind it.

Now, the upshot is there is no way the TC is coming out with the tranny up at stock height, even pushed back as far as it can go - not nearly enough clearance around it. Removing the fluid lines would not help. I doubt anyone has ever done the TC this way. The cover, to replace the bearings, is doable and done, but to service the TC seals, forget it - the rear suspension/crossmember needs to come down. I'll probably just partially drop the rear stuff, the way DR shows in his instructions for installing his rear swaybars - only loosen the tranny bolts (done) and the bolts holding the crossmember to the body, leaving the shock towers and weishach arm bolts and the brake system intact. With a jack under the crossmember, I can drop it and the tranny several inches and then pull the TC straight out (I hope).

BTW, the TC cover bearings are like brand new, even at 221K miles. I think I wasted my time doing this. Maybe I'll find something behind the TC.

Imo000

[QUOTE=Bill Ball;7839482]...........
Now, the upshot is there is no way the TC is coming out with the tranny up at stock height, even pushed back as far as it can go - not nearly enough clearance around it. Removing the fluid lines would not help. I doubt anyone has ever done the TC this way. The cover, to replace the bearings, is doable and done, but to service the TC seals, forget it - the rear suspension/crossmember needs to come down. .......QUOTE]


I found excatly the same thing last winter working on an '89......there was no way in hell the TC will come out, even if the transmission is pushed all the way back. The seal was still good on the one I worked on so I left it alone. Otherwise the rear suspension had to come off.

Bill Ball

I'm hoping just dropped down a few inches. The 4-post lift makes doing anything more problematic. Anyway, we'll see how it goes. I wish I hadn't partially removed the TC already and probably screwed up any seals. But then my entire job would be for naught as my bearing whine and vibration do not appear to be due to TC or TT bearings based on their remarkable condition.

borland

When I replaced the torque converter bearings on my 90' S4, it had less than 90K miles. After I removed the TC housing, I had the same impression about the bearings being still OK.

But, after pressing the drive flange from the torque converter case or housing, I could see that the bearings were actually significantly worn. I think it was hard to tell without disassembly, because the two torque converter bearings are widely spaced in the housing.

Are you saying that you have already pressed out the old TC bearings and replaced them with new?

Bill Ball

No, the bearings are not pressed out yet. I just looked at them and rotated the coupling - really snug, smooth and quiet in all dimensions. Thanks for the comment. I'm hoping this was not all for naught.

Charley B

Bill, sorry I didn't see this thread sooner. I have plenty of time this week to stop by and lend a hand. Name the time.

Bill Ball

Charley:

I'm off to help George today and tveltman tomorrow, so I'm not sure when I'll get back to this. Thanks for the offer. I'll get back to you.

Bill Ball

I finished the TC cover bearings. The old ones were still pretty good, so I'm not sure this was the source of the whine and vibration. I won't know for a few days as I'm also removing the SC and returning the motor back to stock for my biannual smog check.

Also, I actually gave up on getting the TC out. Getting the cover off and rebearinged was not a problem, but in order to get the TC out, the entire rear must come down all the way. So, critcize me all you want, but I just put it all back together. It may leak or still whine, in which case I'll do it the old fashioned way and drop the rear out, as the whine is then most likely internal to the tranny.

Also, another decision - I left the TT alone. The old bearings were very close to new condition and the carriers were still properly located about 10 inches in. The carriers did not want to budge at all, nor did the shaft move even when I simulated a press with a hydraulic jack on the TT situated between two posts in the garage. I'm sure with more effort I could have pressed everything out, but I just decided the TT wanted to be left alone. It's done its job for 221K miles and appears ready to go another 221.

So, I'm just hoping that with the new TC cover bearings the whine and high speed vibration are gone from the drivetrain and it doesn't leak (didn't before) since I did not pull the TC to replace the seals. Maybe slim hope, but I'm always optimistic.

mrdieseldude

I may be asking more of a question here than offering a suggestion, but I notice only Mike Frye has suggested using heat. I used to wrench on outboard engines (boat engines made of aluminum), and an acetylene torch was a mechanics best friend. In many cases, a propane torch would not apply enough heat fast enough to get the job done. I am wondering why this technique is not employed more often. Does "German" aluminum have some weird properties that I am not aware of?

Bill Ball

No, heat is a good idea. The aluminum will expand more than steel like expected and that should help release the bolt. It's just that this area is rather inaccessible to a standard propane bottle torch and to really heat the are might require a long time due to that large heatsink effect from the block. With these upper bellhousing bolts, the main thing that is needed is a LONG 19mm wrench with an angled head. And a Gearwrench type speeds removal. I just bought a long locking flexhead 19mm Gearwrench for th next time. My current flexhead 19mm Gearwrench has gone a bit too floppy and won't hold the right angle.

On another issue as to heat, the WSM calls for heating of the TC cover to 250F when installing the new bearings. That would take a regular oven or a lot of propane. I froze the bearings instead, and they went in very easily. Had I heated the case as well, they probably would have just dropped in. Also, I waited overnight for the cover with its new bearings to warm back up while I froze the driveplate and snout assembly so it would press in more easily through the bearing centers. That's not called for in the WSM, but it worked well.

borland

Bill,

On those factory installed TT bearings, consider that the bearing grease is 21+ years old.