Porsche Repair: 944 Torque Tube, cv joints, torque tube

Question
Hello,

I just finished reading the write up at:
http://experts.about.com/q/Porsche-Repair-829/944-S2-Torque-Tube.htm

First, I have an '87 944S that has a '94 968 engine swapped in it with a 944 S2 transaxle.  The car has a total of about 188,000 miles with about 110,000 on the engine and about 55,000 on the transaxle.  I had a Quaife ATB differential placed in the transaxle about 15,000 miles ago.

I had one of the rubber centered clutches that went bad and just had the clutch replaced with S2 parts.  I had the work done about 700 miles from where I live because that's where it failed.  The work was done by a reputable shop.  I asked them to check the torque tube while everything was apart.

I just drove the car home and after getting off the freeway and driving in some stop and go traffic, their was a noise from the back of the car that sounded like a rattle (sort of like the marble noise described).  At highway speeds it wasn't really noticeable.  When I pulled it into the drive with the car in neutral and the clutch pedal in, it was still making noise.  I turned the car off and then started it up again and the noise was largely gone.  It sounded pretty bad when I pulled in.  After shelling out a large sum for just having the clutch done... The sound is almost like something rattling or vibrating.

Any suggestions on tests to diagnose the problem?

Thanks in advance for any help you can offer.  

Answer
Barry,

I suppose I could take the easy route and say it's the torque tube rear bearing assembly.  After all, to get to the clutch, the torque tube has to be disconnected at the engine...but not necessarily at the transaxle.  So are you sure they checked both ends of the torque tube?

The more likely scenario is you are on your way to blowing out one of the CV joints at the transaxle.  Essentially what you're hearing is indeed marbles...ball bearings the size of large marbles crashing into each other.  In a new CV joint they are positioned and secured by what's know as a "cage".  After a lot of wear, the cage can either break away in one section or split apart freeing a bearing to move about where it never should...banging into whatever else is in there.

What I'd suggest is to go to your local BIG O (for the west coast) type tire retailer.  Tell them you have a safety concern.  Tell them about your noise and see if they perform a "free" safety check.  They deal with CV joints on all cars every day and the good techs can probably "feel" which CV joint is bad.

So you don't get taken...get this gee whiz look on your face and have the tech show you how the bad joint feels compared to the good joint.  I suspect he'll say, there...did you hear that?  He be talking about that loose ball bearing.

Dave