Rennlisters,

I have read many posts on the subject of torque tube repair and bearing replacement options. I now find myself in the position of having to address a TT issue with my 1983 928S I am already upside down in this car, as most of us probably are, but it's still a love affair.

My local shop (no affiliation) is a good one - Rennology of Oak Forest, IL. While in having a fuse replaced for the seats, I had one of the mechanics drive the car to tell me why it "growled" at times when decelerating. He determined that the bearings in the TT are going south on me at 66,000 miles.

I wish I was able to fix these things myself, but I figured out long ago I am best at bringing the beer and pizza for the guys with the wrenches. Anyway, I am give 2 options - a used TT with new bearings from a trusted Porsche source, or a new TT from Germany with new bearings. Cost difference with labor is about $1500. Looking for comments from some of the experts please...and thanks in advance.

 

Superbearings with out a doubt.

 

I see no reason to spend the extra when rebuilt units have been well proven for many years.

 

While the super bearings are fantastic, I prefer to go the Mark A route and just get one of his rebuilds. I've used many of them and think it's the best bang for the buck.

 

Hi Gene,

Be sure you understand just what you are getting for your money with "rebuilt" TTs.

For $500.00 plus shipping, you get all used parts that no longer have the correct tolerances to stay put, as well as incorrect bearings since the original equipment ones are no longer available.

So for your money for the rebuilt TT, you only get two or three new bearings which cost roughly $40.00 or $60.00 dollars total.

Choose wisely since you really don't want to go back in there for awhile.

HTH,

 

The bearings rarely fail. Most people here put up with the excess drive line bearing noise, and to avoid engine damage (TBF), make frequent pinch clamp checks (for automatics).

 

Plus..how does your mech know its NOT the converter bearings? replace those while your in there also.

 

Most S4's I see either have had them replaced or need for them to be.

 

The factory part sounds silly expensive for nothing special, rebuilt units have a long history of working well, and if you expose the car to a lot of miles and/or abuse via track etc have it rebuilt with premium bearings.

+1 on its very hard to tell what the driveline problem really is until you get inside, so be sure to have everything on both ends of TT checked. After replacing the clutch and TT my noise turned out to be the transmission input bearing (think torque converter bearing for an AT).

 

I clamp the TT down to a heavy steel table and spin it with a section of twine, like you would a top, you will know real quick if they are making any noise, then I go ahead and replace everything.

 

Since I've got a 'rebuilt' here that I'm planning on installing, are you saying that all of the components are all used parts in there? I thought you were charging about the same amount for one of your rebuilds with the new bearings.

What am I missing?

 

I just went through this process and I feel your pain! This is definitely not a job you want to do again! I did do this job myself and it wasn't all that bad. I will suggest since you are having a mechanic do the job make sure he also replaces the transmission lines as well otherwise in a few years you will be back in there getting them changed because of dry rot(age). Just about every 928 I have ever owned the transmission lines are dry rotted and leaking. I also recommend you have replace the rear torque converter bearing (50% of the time thats growling your hearing).

I went with a rebuild unit from Mark at 928 international and I have 10k miles on it so far and its been quiet as a drum. Mark was great to deal with as well. I also talked to Constantain on the phone as he helped me troubleshoot a few issues with putting everything back together. There both great guys that have offered a lot to the 928. I honestly believe you can't go wrong with either unit. However I believe the Superbearing one will last longer in the long run because of the all new parts factor. Good Luck!

 

The only thing that is used with the SuperBearings is the tube and the shaft.
I have over ten thousand miles on one of Marks rebuilds and it is still working great.
I am really impressed with the SuperBearings and have installed them at my shop.
Looks like I will be doing another set next week.

 

Hi Sean,

The rebuilt units from other vendors use all original parts to include the bearing holders and the bearing inserts/spacers that hold onto the drive shaft. They have seen many heat cycles and their tolerances are no longer as new. This will cause the bearing units to move around and the drive shaft will spin in the bearings since the inserts/spacers just don't grip as well on the drive shaft anymore. The only new parts are the actual bearings themselves which are not the correct ones Porsche initially specified.

Our Super Bearing units are all brand new parts and use a larger bearing too. They have also been changed from the original design to take care of known problems with the old ones.

Disclaimer: We can no longer sell the Super Bearings on Rennlist since we are no longer Rennlist Sponsors.

Super Clamp is still fair game since another Rennlist sponsor carries them.

HTH,

 

BTW my comment about "spending the extra money" was referring to new. Constantine does make a very nice product if you want to install the parts yourself.