Diff whine (I think)

[simon]

Having just put new bearings on my diff I now have a whine when I come off the throttle. I do not have the whine or any clunking on acceleration, just when I come of the power. Is this whine caused by the diff to pinion backlash or something else?

 

Cheers Simon

[Rhodri]

Did you set the bearing preload? If that is correct then most likely the mesh of crownwheel to pinion is wrong.

[simon]

Did you set the bearing preload? If that is correct then most likely the mesh of crownwheel to pinion is wrong.

 

Preload? The manual formula refers to runout as measurement A and diff fore and aft as measurement B, not too sure on what you refer to as bearing preload? Sorry to be a tad thick?

 

Cheers Simon

[Rhodri]

I may well be wrong with your axle, but on two Fords and a Toyota pick-up axles in that I have done the pinion bearings have to be preloaded- forced towards each other a set amount. The side bearings also. Both of these axles are Timken , or banjo style axles. Have you searched the net for rebuilding a diff? I also bought an old pinion bearing preload tool to measure it. From memory the pinion on the Toyota was 15 inch/pounds NOT 15 foot/pounds that most normal torque wrenches read. The meshing has to be right to avoid a noise in the diff and this goes to pot if the bearings are not preloaded.

 

Someone will tell me that none of the above applies to the TR7 !

[mikehardwick]

Rhodri is right - diff reassembly (crown wheel and pinion) requires the use of collapsible spacers, mystic calculations and other examples of the dark arts. Rebuilt diff from a known supplier is the route I would take.

 

Mike