Whinning noise in rear

[mjb765]

I have a whinning noise in the rear only under load. In neutral or coasting in gear the noise goes away. 8 3/4 rear......Sound like something set wrong in the chunk?? Backlash?? I'm thinking a bearing would make noise all the time?? Axle end play is good.

[Bullitt-]

Is this something different than before?  Rear Wheel drive vehicles tend to have a "whine" under load. I was discussing the noise our Lincoln Navigator made with a mechanic & he said I was just not used to having the rear so near the passenger compartment.

[mjb765]

I put a used center section in and now have the noise. Wondering if it might be a backlash issue???  No vibration or anytthing else, just the whine under load.

[mojavered]

If it was a backlash issue, wouldn't you have a clunk upon take off?  Or would that be something else?

[ntstlgl1970]

Rear pinion bearing. Is this a 489 or 742 case? If it's a 489, the crush sleeve may have gone away which will take out the bearings. Same deal with the navigator.

[mjb765]

It's a 489 case.  The whine is not too bad, but I hear it. Can I still drive it while I have my other center rebuilt?

[Supercuda]

Yes, but don't hammer on it while driving. That would be pulling the pin on this grenade. I like the "normal function" comment about the Lincoln. I don't think I want that guy working on any cars for me.

[Bullitt-]

I like the "normal function" comment about the Lincoln. I don't think I want that guy working on any cars for me.

   It made the same noise from new-65K when we sold it...was not that loud but you could tell a difference when on/off the gas.

[mjb765]

Yes, but don't hammer on it while driving. That would be pulling the pin on this grenade. I like the "normal function" comment about the Lincoln. I don't think I want that guy working on any cars for me.

Good...thanks...

and far as normal noises go--I had a backlash clunk on a brand new truck I bought almost 20 years ago and several dealers and the factory said it was "normal"....not a happy noise, but I put 125,000 on the truck and never had any problems. Factory and dealer normal is sometimes different than what we would like.