e34 M20 Final Drive

[chinlai]

My ride's final drive is taking its final drive.. The amount of free play that it has is quite irritating, and there's a grinding sound that comes up when I cruise at around 90km/h.. Is there anyway to save (recondition) the final drive? I've been bothering my mechanic a few times already with putting in second hand final drives, but the drives all seems to have that same problem (the grinding sound at 90km/h)..Does anyone know if I can get a new final drive and how much it would cost?

 

[moots]

chinlai,
my rear diff also has some amount of play in it but it doesn't give any unwanted unnecessary loud/grinding noise.and i have clocked 430,000kms.it's strange to have changed the diff only to have the same noise recurring.
i suspect yr rear subframe bushes are worn.if is is worn,the subframe could make contact with the chasis,transmitting all mechanical noise into the car.

 

[E34EuroTouring]

Chin,

Best to look for a second hand rear diff from a chop shop. These things should not be opened as they are built to last a long time and replaced as one unit. If you can get an LSD one, it would be a great upgrade. Or else, a newer open diff will do. Good luck.

PS: Have you drained and put in new diff oil in your diff ?. It may be a case of lower oil level causing A-clutch pack to squeal.