Torque tube bearings?
12-16-2011, 11:58 PM
#1
Three Wheelin'
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Torque tube bearings?
Hi folks,
Just noticed a new problem with the GTS (there's a stack of other stuff to fix on my list, which I was planning to start week-after-next, but this is new): Above 5500 RPM, I get serious noise from underneath and significant vibration of the shifter. The car has about 107K Miles on it. Is this how torque tube bearing act when they're done?
Assuming, yes, how much work is it to change them, and would I need two of Constantine's, or three? (car is not a racer, but it is somewhat modified, with more aggressive cams, X-pipe, free-flow cats, and a Sharktune to go with those parts - OTOH, I'm at 6500 feet elevation, so down about 20% from sea level horsepower).
Thanks,
Paul
Just noticed a new problem with the GTS (there's a stack of other stuff to fix on my list, which I was planning to start week-after-next, but this is new): Above 5500 RPM, I get serious noise from underneath and significant vibration of the shifter. The car has about 107K Miles on it. Is this how torque tube bearing act when they're done?
Assuming, yes, how much work is it to change them, and would I need two of Constantine's, or three? (car is not a racer, but it is somewhat modified, with more aggressive cams, X-pipe, free-flow cats, and a Sharktune to go with those parts - OTOH, I'm at 6500 feet elevation, so down about 20% from sea level horsepower).
Thanks,
Paul
12-17-2011, 12:26 AM
#2
Race Car
Not the bearings, but this is what happens when one or more of the carriers gets loose and migrates away from its designated position. If it's a 5-speed, it could also be the clutch arm bushing disintegrating away. If it is the TT and you let it go too long, the clutch guide tube will get loose and bad things can happen.
I went with Constantine's bearings. I believe you need 3 for a 5-speed.
Dan
'91 928GT S/C
475hp/460lb.ft
I went with Constantine's bearings. I believe you need 3 for a 5-speed.
Dan
'91 928GT S/C
475hp/460lb.ft
12-17-2011, 12:54 AM
#4
Three Wheelin'
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Hmmm... I just remembered that I have a zero deductible extended warranty on this car. It only covers the powertrain, but I would expect torque tube to be very much in the power train....
12-17-2011, 01:32 AM
#5
Under the Lift
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I agree with Dan, although sure, the bearings could be bad as well. I saw this with a 5-speed that had migrated bearing carriers. The owners described it as vibration above 5000 RPM, although I could feel it somewhat throughout the entire RPM range. I diagnosed it by removing the lower bellhousing cover and using an unfolded coat hanger to probe down the TT. I found the bearing over 2 feet down the tube. It should be 10-12 inches. Regardless, the treatment is the same.
Interestingly, I found migrated carriers in an automatic 928 and there were no real signs of it - no vibration or noise. In automatics, the shifter does not make contact with the TT. In that case, the bearings seemed good, so I just reloacted the carriers to where they should be and pinned them inplace.
Interestingly, I found migrated carriers in an automatic 928 and there were no real signs of it - no vibration or noise. In automatics, the shifter does not make contact with the TT. In that case, the bearings seemed good, so I just reloacted the carriers to where they should be and pinned them inplace.
12-17-2011, 02:05 AM
#6
Rennlist Member
My bearings had migrated, the carriers were in such a poor condition when I removed them I knew they weren't going back, I ordered Constantine's super bearings, i didn't want to mess with the TT again, when you compare them with the originals you know you have a good deal.
While you're underneath, fit some new the transmission mountings, if they've never been replaced, there 18yrs old and on the way out.
While you're underneath, fit some new the transmission mountings, if they've never been replaced, there 18yrs old and on the way out.
12-17-2011, 05:36 AM
#7
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Hi Paul,
All 928 5-speed torque tubes (TTs) came with three bearing units and a vibration dampener inside.
As an added benefit, when you use three of our Super Bearings the dampener, which can come apart with age, doesn't have to be re-used in the TT. That's because the Super Bearings were designed to replace the weight of the OE dampener.
By the way, we are now working with a shop in Colorado who just ordered a bunch of our 944 Super Bearings and is also wanting to get involved with rebuilding 928 TTs. Might be someone you want to have this work done by if you are not planning on doing it yourself.
Happy Holidays,
All 928 5-speed torque tubes (TTs) came with three bearing units and a vibration dampener inside.
As an added benefit, when you use three of our Super Bearings the dampener, which can come apart with age, doesn't have to be re-used in the TT. That's because the Super Bearings were designed to replace the weight of the OE dampener.
By the way, we are now working with a shop in Colorado who just ordered a bunch of our 944 Super Bearings and is also wanting to get involved with rebuilding 928 TTs. Might be someone you want to have this work done by if you are not planning on doing it yourself.
Happy Holidays,
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12-17-2011, 07:26 AM
#9
Rennlist Member
I just experienced this with my GTS. First the ball cap on the forward shift arm disintegrated. After replacing that part, I noticed a spectacular buzzing transmitted through the shifter above 4500 RPM - the forward TT bearing had migrated 25" down the tube. I'm sure that all of this was related.
I pulled the TT and shipped it to Constantine who did the R&R. What an impressive guy! Three superbearings were installed. Bottom line, the vibration is gone.
During this job, I also installed a Short Shift kit (Lizard). That mod changed everything about shifting the car! Highly recommended.
If you stay with the factory shift assembly, now is the time to replace the insert on the ball cap, inspect the 'shift arm bearing', and the foam/rubber insulation between the TT and drive line tunnel.
Since you have to shift the transmission rearward to drop the TT, I also used the 'opportunity' to replace the transmission mounts, the transmission oil lines, and a leaky input shaft seal.
I pulled the TT and shipped it to Constantine who did the R&R. What an impressive guy! Three superbearings were installed. Bottom line, the vibration is gone.
During this job, I also installed a Short Shift kit (Lizard). That mod changed everything about shifting the car! Highly recommended.
If you stay with the factory shift assembly, now is the time to replace the insert on the ball cap, inspect the 'shift arm bearing', and the foam/rubber insulation between the TT and drive line tunnel.
Since you have to shift the transmission rearward to drop the TT, I also used the 'opportunity' to replace the transmission mounts, the transmission oil lines, and a leaky input shaft seal.
