Hello to all,i have a 3dr sierra cosworth,and i have a noise for example with 4th gear from 3000rpms - 2600rpms when i leave the throttle ,from under the car about in the end of gearbox and in the rear place like grrrrrrr like something metalic part have vibration or something knocking and comes noise, all the parts are new, drive joints,rebuild prop-shaft with all new,rebuild gearbox,rear diff with 65000km,wheels bearings new,also i tested the car with SAE140 gear oil and the noise still there,so does anyone had the same issue?any idea? thanks in advance

Thanasis

 

Exhaust hitting floor pan??
Centre prop mount tight?
Handbrake cable loose?

 

Εxhaust no hitting floor etc..
centre prop mount have new bearing
Handbrake cable is ok also


At 99% is inside the diff from planet gears,in this place is weak with result the gears plays when the drive shaft works without load,i tested the car today in the rear wheels on air with the 4h gear at idle and after i catch the right drive shaft with hand and the noise stops!

 

I had an apparently rebuilt gearbox when I bought my car last year, weren't sure what it was at first and thought it was the exhaust vibrating.
It got noisier and noisier till eventually I couldn't select gears easily and the bearings had completely gone in the gearbox.
It made awful noises on overrun and at certain revs

Cheers Paul

 

Ι don't have awful noise,just when i leave the throttle about 3000-2600rpms just one like 'gourrrrr' and the noise comes from the rear and right side of the car,thanks
Thanasis

 

I had a really weird experience with my sapphire with a similarish noise - it turned out to be the starter motor of all things!