Torque Tube rebuilding

Granite 944 · 10-12-2005, 03:42 PM

I just looked at one of the recent posts on torque tube compatability, and I'm thinking about replacing the bearings in at least one of the tubes I have from a parts car, then swap it into my '83. I really haven't researched it out much lately, but I would sure like to hear from anyone who has done this themself. Any links to procedures on this, or suggestions on part numbers for the bearings, or anything regarding this would be greatly appreciated!

Anyone that can tell me what some of the symptoms of a bad torque tube bearing are, would also be of great interest to me right now. My '83 has what I would call a very distinctive bearing/metalic howl (dry roller bearing type noise) to it from about 25 to 65 mph (still there otherwise, just not as noticable). I've not replaced rear wheel bearings on this car, but cannot get the sound to change when weaving, turning or such. The tranny is in good shape, no growling gear noise, or shifting issues at all. I've not pulled the rear brake rotors off for some time, and know the E brake is out of adjustment. Could this be a source of this noise? I suspected some it to be tire noise, but, put a different set of tires on it for a while in the rear, and if anything, it got a little worse, but, it does get a lot quieter on brand new asphalt roadways, I'm getting some confusion here. Car has approx. 170K miles on it. I've thought about putting car up on blocks, and running it in gear to see if I can isolate the sound, as I really can't tell where its coming from while driving ( my hearing isn't so good anymore....happens when ya get old and cranky ya know).
TIA

AznDrgn · 10-12-2005, 05:23 PM

Procedure

You will need to remove the transmission, and also drop the rear suspension. There really is no other way to get it out. The bearings are made by FAG, but my replacements were made by SKS. The four bearings cost me a total of fifty US dollars. The bearings are press fit into the housings they live in. I paid twenty dollars to have a machine shop RR the bearings from the housings. The bearings might be available at an outo parts shop, but only if you have the bearing number from the old bearing. Since the torque tube is not considered rebuildably by Porsche ( who would rather screw us) the auto supply place would not have the bearing listed in theier catalogs. a bearing supply place would be better.

Once you have the tube stand it up vertical, with a drip pan underneath. Pour in a cup of motor oil, let stand over night. it will get things slippery inside. No longer than over night, because you do not want the oil to soak the rubber parts inside.

Next, get a 5 foot length of half inch id electrical conduit. this fits over the actual drive shaft, where the pilot bearing would be. Now hammer on the conduit until the shaft is driven out the other end of the tube. Now measure and record exactly where the bearing shells are located. You will want to reinstl them in the same location later. Once this is done, get a 5 foot section of 2 inch id PVC drain pipe from the plumbing store. Drive that pipe out the other end with a heavy hammer. the bearings will come loose now.

Clean everything up well. it might be good to clean the bearing housing with dishwashing liquid.

you will notice a nylon bushing inside each bearing. remove them carefully, I cannot imagine trying to get a replacement.

Now have the bearing pressed out from the housing and replaced.

Installation is done by making the outside of the rubber housings slippery with dishwashing liquid, then pressing each one back into place with the drain pipe. Make sure that the bearings end up in close to the same place, or the torque tube will vibrate. Last of all, drive the drive shaft into place by whacking on the big end of the driveshaft. A block of wood between the shaft and the hammer is reccomended.

This would be a good time to replace your clutch, since you will never have as much room to work. It is also a good time to drop the gas tank for cleaning and to replace all the rubber hoses that make the car smell.

Granite 944 · 10-12-2005, 06:53 PM

Wow! Thanks! I was gonna PM you and ask about your procedure.

I have my serious doubts that the noise I'm experiencing is really the torque tube in my car, but I still want to get one ready for future use(which may come sooner than later). The gas tank, is gonna need to come out sometime soon on this one anyway, since I know theres a leak somewhere on top of it, and thats when I may swap this tube out just for the sake of it, considering the mileage on it.
Thanks again!

Other comments and such very much welcomed.

AznDrgn · 10-12-2005, 08:02 PM

Never done the job myself since what I thought as a bad torque tube was actually my own stupidity. For some reason or another on my 924 I forgot to bolt up one of the motor mounts so it was just resting on the cross member. Are you still experiencing the same symptoms as you were in your post on Rennlist? Those symptoms sounded like a bad TT, messed up mounts, or something funky going on with your clutch, your bearings could also have walked since they are just held in there by those bushings. I've heard of people tapping and threading in 4 bolts to keep it from walking.

Granite 944 · 10-13-2005, 04:14 PM

Quote:

Originally posted by AznDrgn
Never done the job myself since what I thought as a bad torque tube was actually my own stupidity. For some reason or another on my 924 I forgot to bolt up one of the motor mounts so it was just resting on the cross member. Are you still experiencing the same symptoms as you were in your post on Rennlist? Those symptoms sounded like a bad TT, messed up mounts, or something funky going on with your clutch, your bearings could also have walked since they are just held in there by those bushings. I've heard of people tapping and threading in 4 bolts to keep it from walking.

I don't remember putting up one on Rennlist about this noise. The gas tank problem, yes, some time ago, and I still haven't gotten to it.

I just noticed a bit ago, that Clark's garage has a pretty good write up on this torque tube job also. It wasn't there the last time I remembered. I 've got to keep going back and checking that place often! They keep adding and revising the procedures there frequently anymore, it looks like. So much for my printed out book of Clark's.

I've got some updating to do.

Thanks!