svx604

Timing belt and balance belt, had been done and checked by different mechanics. Clutch, engine mounts, spark plugs, new.
Engine is smooth overall but it's hard to use it above 4500 rpm due to shift vibrating so much. Any ideas?
Would there be a need for timing to be checked?

968workaholic

Does it vibrate only in gear? Out of gear? Clutch depressed? Clutch not depressed?

svx604

When in gear clutch not depressed. Upon acceleration for an upshift.
I have not tested it out of gear but will do so to check.

931guru

Bent driveshaft within the torque tube.

svx604

Thanks, a bit much to swallow but I can accept it since I'm adventurous in wanting to rebuild the tranny myself.
Now would you mind letting me know if you've experienced this issue or have heard others (forum link) that have and where I can get parts / rebuild for the torque tube? Many thanks.

jhowell371

Did you check for chunks of rubber in the bell housing? Your clutch's rubber center maybe coming apart.

svx604

Thanks but as mentioned in first post clutch has been done recent, and yes I did experience the rubber doughnut failure.

mel_t_vin

Who did the belts and clutch...corner garage, Porsche/German specialist, or dealer?

Which clutch parts were used...ebay aftermarket or OEM Sachs? What parts were replaced...disc, pressure plate, release bearing, and pilot bearing? Was the flywheel cleaned/resurfaced prior to reassembly?

svx604

Clutch was done by a reputable garage that regularly services mainly Porsches and some exotics. New clutch is Sachs kit and all parts that should be replaced were done, pilot, rear main seal, clutch bolts etc. fly was machined. The only thing that wasn't done (and nor have I heard of only until recently) is balancing the clutch with the flywheel but I really don't think this would cause a harsh vibration at 4000rpm (I'm recomfirming it is 4k rpm and not 4500rpm). This is in gear under load at 1st 2nd 3rd gears ( I have not tried 4th or 5th).
Balance and Timing Belts were done by Porsche (balance belt done incorrectly and corrected by this reputable garage, timing belt was checked at the same time).


I am wanting to find another way to confirm the my torque tube rotating axle is in fact bent before taking things apart. I am aware the bearings are a common problem but I don't hear any bearing noise. Any checks I can do through the pinch bolt window at the transmission?

snb13

Make sure your O2 sensor hasn't come loose in the bung.

mel_t_vin

Sounds like all bases were covered.

Once encountered a situation similar to yours...sporadic drive line vibration at given RPM. Root cause was chipped splines on the drive shaft. Evidently, as the clutch was disengaged/engaged, the disc would not always be centered between the fly wheel and pressure plate. Solution was to take everything apart and replace with a [rebuilt] torque tube.

Hopefully, your solution is less involved/invasive.

mel_t_vin

Out of curiosity, how long had you owned/driven the car prior to replacing the clutch? Suspect it would be difficult for the shop to bend your drive shaft while replacing the clutch.

931guru

Not difficult at all. It just takes your mechanic to move the torque tube back a bit and leave it hanging on the bell housing while he does something else.

svx604

Thanks for the input, I have a good idea what I'm up against now, I think. I'll accept it since I'm aware this car is "special". So I look forward and brace.
I cannot assume the shop was in wrong doing since it's the most reputable Porsche service garage in the city. I only know I went to thee place for the job.

I am a new owner and received the car just when the clutch rubber doughnut was dying, and pretty much right when I purchased the vehicle it died, though the previous owner nor PPI found this fault. And I understand this was possible since the rubber was intact and then not intact. I'm thinking the literally few minutes that I drove it failed, could had actually damaged the spines, if in fact they are damaged. It could be the bearings as well, though there's no bearding noise I'm aware of.
Either way I need a rebuilt TT.

Could you direct me to a place/link/shop to attain a rebuilt TT? Thanks.

968workaholic

If you disconnect the coupler between the trans and the torque tube, it would eliminate any chance of the vibration coming from the trans. If it still does vibrate at 4k, push in the clutch. If it goes away then the torque tube if definitely the problem