I had work done on the rear diff of my 09 F150 Platinum a few months ago. Ever since, I've noticed a whining noise coming from the rear end when pressing the accelerator. If I let off of the accelerator, the whining goes away. Everything I've ready so far indicates that the shop did not reset the preload on the pinion bearing.

Is this something I can do myself? If so, can someone give me some tips on the proper way to do this? Does the rear diff fluid need to be drained or do I just have to drop the drive shaft?

Thanks.

 

I would take it back and voice your concerns, sounds like rear may not have been set up properly.

 

The whole thing needs to come apart. The crush sleeve is single use for preload.

 

That's my thinking also. Usually preload problems (inadequate preload, that is) will manifest upon decel and its generally a chatter rather than a whine. I suspect a contact pattern issue.

To the OP, The really slick way to set preload is to shim the pinion between the bearings, and then the nut torque is not what determines the preload (unless it comes loose of course). In this scenario, once the shimming is correct, you just hammer the nut down GD tight and you're done. It's more time and effort initially, but it makes future pinion seal replacement a breeze. I personally do this when I have one apart because I run around in straw covered fields and have wrapped a couple driveshafts over the years and had to replace the seal. -- Yes you can replace the seal without replacing the crush sleeve on a conventional set-up, but this makes it a lot easier and takes the guesswork out of it. Older cars/trucks and most all modern heavy/comml trucks still do this. The crush sleeve was devised many decades ago to speed up the assy line, and FWIW the sleeve actually has nothing to do with preload. It simply provides extra resistance for the pinion nut so it isn't prone to loosening up over time.

 

FYI, if you ever have to remove a pinion nut to change a seal, use a punch to mark the shaft and nut in relation to each other. Then remove the nut while counting the number of turns it takes to remove it. Change the seal then when reinstalling the nut turn it back on the same number of turns and stop when the 2 punch marks line up. This will put the nut back in the exact same spot without having to change the crush sleeve.

 

This method works, except... re-install the pinion nut a couple degrees of rotation tighter than it came off. That way you have positive pressure on the sleeve/nut, and since the bearings are now worn-in, they can handle a little extra pre-load without a problem.