Ok... I've exhausted my self in the past month trying to do research as to what my problem is with the car.
Problem..
The car is set up like this when the thud is heard.
Just shifted upward durring acceleration. Clutch has been released into the new higher gear... the exact moment when the throttle is touched (provided it was a low RPM shift so no need to match throttle with release of clutch) to accelerate in the new gear... the thud is present.
Drive shaft appears to be lose.. but I do not know the allowable limit on shaft rotation when car is off. When wiggled back and forth... a faint metal on metal sound is heard. Sorta the same as the driving thud... but very faint. Conclusion has been made that it is something dealing with the drive shaft.
Things checked and or replaced....
Guibo
Center support bearing
Rear subframe bushings
Front diff bolt
All suspension in the rear (as the entire suspesion has been replaced... noise was present before installation of new suspension)
I'm am now lost as to what it could be.
Only thing that I have come to think to be the problem is... the car has 171k miles on it... the input shaft from the tranny into the drive shaft or the part that fits over the shaft from the tranny has been worn. Allowing play between the tranny and drive shaft resulting in the noise and play in the shaft.
Any imput as to what this problem could be are welcome. Please note that I have read anything and almost everything pertaining to thuds, drive shafts, differential movement and tranny problems on bf.c , m3f.c and various other sites.
Thanks in advance for your help,
Les
Problem..
The car is set up like this when the thud is heard.
Just shifted upward durring acceleration. Clutch has been released into the new higher gear... the exact moment when the throttle is touched (provided it was a low RPM shift so no need to match throttle with release of clutch) to accelerate in the new gear... the thud is present.
Drive shaft appears to be lose.. but I do not know the allowable limit on shaft rotation when car is off. When wiggled back and forth... a faint metal on metal sound is heard. Sorta the same as the driving thud... but very faint. Conclusion has been made that it is something dealing with the drive shaft.
Things checked and or replaced....
Guibo
Center support bearing
Rear subframe bushings
Front diff bolt
All suspension in the rear (as the entire suspesion has been replaced... noise was present before installation of new suspension)
I'm am now lost as to what it could be.
Only thing that I have come to think to be the problem is... the car has 171k miles on it... the input shaft from the tranny into the drive shaft or the part that fits over the shaft from the tranny has been worn. Allowing play between the tranny and drive shaft resulting in the noise and play in the shaft.
Any imput as to what this problem could be are welcome. Please note that I have read anything and almost everything pertaining to thuds, drive shafts, differential movement and tranny problems on bf.c , m3f.c and various other sites.
Thanks in advance for your help,
Les