differential noise continues....

[radcar44]

I had the whine at abt 60 mph which would decrease with letting off accelerator. I also had a deep rumble which started about 70 mi./h, but greatly reduced at 80 mi./h, and would not decrease with removal power.

I had both carrier bearings and the pinion bearing replaced, watching every step of the process. there was very little metal in the case or in the old oil and the ring and pinion gears were not pitted and did not appear to be damaged in any way. After the differential was reassembled and topped off with new fluid, a test drive revealed no change - both noises were still present. the rumbling sound now seems even more pronounced and can be felt in the steering wheel.

Any ideas on what is causing these problems? Could the whining and rumbling sounds be generated by the transmission?

Any help would be greatly appreciated

Thanks.

 

[icepickjazz]

Did you have the actual ring and pinion gears replaced or just the bearings? It's doubtful replacing the bearings w/o replacing the ring and pinion gears isn't solve the problem. All the ford tsb's call for replacing ring and pinion gears.

Regarding the rumble. Do have 4x4 or 4x2? Check TSB 05-16-4 or 05-20-11. Do either of these apply to your situation?

 

[Geologist]

Have you also verified that some (if not all) of the noise is not coming fom the rear wheel bearings? I understand noisy rear wheel bearings can be mistaken for rearend noise in these SUV's.

As for the rearend overhaul, if the assembler shimmed it properly (to specs) then it should not be noisy, unless you didn't actually replace the ring and pinion gears (as icepickjazz pointed out).

Edit: I believe the ring and pinion are a matched set, i.e. you can't just get a new pinion gear and use your old ring and expect it to run right.

 

[radcar44]

Thanks for the tips. The ring and pinion were not replaced, but the wheel bearings and hubs were, as well as the carrier and pinion bearings and U-joints. No shimming was done.

Took it back this morning and all they would do was "tighten" the pinion nut. No help. They threw up their hands and I took it to another shop. While I watched, they put it on a lift, then ran it up to 70 mph - the rear wheels were bouncing like crazy. Tire balance!

After balancing and rotating the tires, the noise was gone!

I live and learn....