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Join Date: May 2002
Location: Tioga Co.
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diagnose this noise

Rear of the car raised. In gear, when the clutch is let out a little shudder, and muffled rattle from the rear, quickly goes away. Idling in 5th gear the noise is constant (30-35mph) raise the speed, and the noise goes away.

Also, with the car running releasing the clutch causes a thunk, but when not running there is no noise. Related?

Tried sourcing the noise with a screwdriver against my ear, and wasn't very successful. Doesn't seem to be CV's. Noise seems most pronounced at front or rear of tranny. Torque tube? Input shaft bearing? Ring and Pinion?

Car hasn't been run all winter, noise wasn't there when the car was put up. Replaced a trailing arm over the winter. New clutch last winter, but it ran fine until it was put up this winter.
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'86na, 5-spd, turbo front brakes, bad paint, poor turbo nose bolt-on, early sunroof switch set-up that doesn't work.

Malo periculosam, libertatem quam quietam servitutem.
Old 04-05-2005, 07:50 AM
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Lots of noise in a drive train when there is no road resistance.

AccDec (Acceleration/Decceleration) on the road is more important. A clunk in the drive train when AccDec'ing is a sure sign of a bad clutch disk. Could also be the coupling at the trans or a bad/loose CV joint(s).
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Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
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Old 04-05-2005, 07:24 PM
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OK, an update. The noise (which is hard to explain, thunking?) is present with road resistance. When moving, clutch in or out, (car isn't insured, so I only have gone in 1st and 2nd, and coasted on a hill).

The noise can be felt when driving, it is arythmic, and actually feels and sounds like the exhaust is loose and banging into the car from underneath. With my fist hitting the tranny from underneath I can produce what I think might be the noise (sounds like a thunk from tranny/torque tube mating area), but I honestly don't know what it can be, it doesn't seem to be the exhaust or shift rod. It almost seems to be worse when driving over uneven ground.
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'86na, 5-spd, turbo front brakes, bad paint, poor turbo nose bolt-on, early sunroof switch set-up that doesn't work.

Malo periculosam, libertatem quam quietam servitutem.
Old 04-06-2005, 07:49 AM
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If the "noise" is in time with wheel rotation then start looking at the wheel bearings and drive shafts. Could even be a warped rotor rasing hell with the pads.

If the noise is when you get on / get off the gas in gear then thing drive train; clutch, trans and axles.
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Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 04-06-2005, 12:44 PM
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It's been a while. Time's been eaten by other car maintenance, and a little comp time for the spouse (put a deck on the house, so that I can spend some more time in the garage).

Anyhow, believing the noise to be serious and an indication of trouble in the tranny or torque tube, I started to remove the tranny. To make a long story short, not too far into the process I determined that the noise was caused by the torque tube coming into contact with the aluminum piece that runs in front of the torsion bar housing. Flat plate, crosses the tunnel and held up by 4 bolts. What would cause the torque tube to contact this piece, and how can I get the proper clearance?
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'86na, 5-spd, turbo front brakes, bad paint, poor turbo nose bolt-on, early sunroof switch set-up that doesn't work.

Malo periculosam, libertatem quam quietam servitutem.
Old 04-21-2005, 06:08 PM
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Replace the trans mounts.
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Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 04-21-2005, 07:16 PM
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Thanks.
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'86na, 5-spd, turbo front brakes, bad paint, poor turbo nose bolt-on, early sunroof switch set-up that doesn't work.

Malo periculosam, libertatem quam quietam servitutem.
Old 04-22-2005, 03:09 AM
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