Hey all,

So my FB's rear end is possibly on its way out soon. There is a whump whump whump noise coming from the driver's rear area of the rear end, and I checked for heat near the center of the rims after a lot of highway driving to no avail.
I have spoken with a few folks about it, and it seems to be a consensus to possibly end up being a pinion bearing or something like that.

The noise has gotten quite a bit worse and now makes noise at any speed above 40 mph.

 

Oops! this is for a 1981 FB with GSL rear end conversion. I am not sure what year the rear end is but I know it is a large flange as stated above.

Thanks!

T

 

If the noise is coming from the wheel bearings, the sound usually changes when cornering. Otherwise, it may be difficult to identify noises in the diff, as opposed to driveline or tire noises.

Jerry Wright at Jerry's Little Cars in Kent is very knowledgeable, can almost certainly identify the problem, and I believe he can rebuild it for you. But be advised it is not cheap. That is why these rear ends have gotten so expensive. If you have one of these GSL rear ends complete and in good condition, and anyone offers to buy it for less than $450 -500, you are being robbed. The diff alone will cost about that from a Mazda wrecking yard.

 

Odd's are that it is a wheel bearing and anyone who can turn a wrench can do thoughs.

 

Thank you Ben, Allen.
I will check out Jerry's shop to see what it will cost to look/replace parts.

-Tim

 

Change the oil first. That really is the first thing you should do.