Hi all. I'm hoping for some diagnostic help. I've searched and read several "clutch release thunk" type threads, but I haven't found one that seems to describe quite the same behavior.
The Jeep is an entirely stock 2001 TJ with the 4.0 and a NV3550. With the engine running and transmission in neutral, quickly releasing the clutch gives a pronounced "thunk" type sound, but it's silent if I release the pedal very slowly. As shown/heard in this video:
There's no thunk when pressing/releasing the pedal while the engine is off, whether in neutral or in gear. I also don't hear this while driving, though I can elicit what I believe to be a suspension/driveline thunk (worn control arm bushings?) if I press/release the clutch while coasting in gear (15mph in 2nd, say). On the other hand, I don't hear anything if I press/release the clutch while coasting in an artificially high gear (15mph, depress clutch, shift to 4th, rapidly rapidly release clutch with no throttle).
The pedal to master-cylinder linkage under that dash appears solid (no noise or undue movement coming from it while cycling the pedal by hand), but I'm having a hard time getting eyes on the slave cylinder while moving the pedal. A lot of what I've read points to suspension or driveline, but I'm not understanding how that would cause this noise in neutral while the vehicle is not moving? Any suggestions are appreciated.
The Jeep is an entirely stock 2001 TJ with the 4.0 and a NV3550. With the engine running and transmission in neutral, quickly releasing the clutch gives a pronounced "thunk" type sound, but it's silent if I release the pedal very slowly. As shown/heard in this video:
There's no thunk when pressing/releasing the pedal while the engine is off, whether in neutral or in gear. I also don't hear this while driving, though I can elicit what I believe to be a suspension/driveline thunk (worn control arm bushings?) if I press/release the clutch while coasting in gear (15mph in 2nd, say). On the other hand, I don't hear anything if I press/release the clutch while coasting in an artificially high gear (15mph, depress clutch, shift to 4th, rapidly rapidly release clutch with no throttle).
The pedal to master-cylinder linkage under that dash appears solid (no noise or undue movement coming from it while cycling the pedal by hand), but I'm having a hard time getting eyes on the slave cylinder while moving the pedal. A lot of what I've read points to suspension or driveline, but I'm not understanding how that would cause this noise in neutral while the vehicle is not moving? Any suggestions are appreciated.
