1994 F350 7.3L diesel idi non-turbo SRW 2WD
Recently had a rear wheel bearing go out which was the result of a bad pinion seal leaking out most of the fluid.

So, replaced all bearings and seals on both sides as well as the pinion seal. I think I may have blown it with the pinion seal replacement. I followed the 'makuloco' video marking the location of the pinion yoke and nut on the differential. However, doing the rear bearing at the same time the pinion gear shaft may not have been in the same location.
Upon reassembly and road test I now have a chatter when decelerating at anything over about 40mph. Also, upon checking the drive shaft there is now some play in the pinion yoke which I don't recall having before disassembly.

Would the alignment of the pinion yoke be critical? Or, is it possible the yoke had play which I didn't realize? Anything else which could be causing the chatter on deceleration? Do I simply need to replace the pinion yoke?

Long winded post but hoping someone can offer suggestions on how to correct the problem. Thanks.

 

Also long as all your marks line up you should be good. You got some play at the pinion , you probably just need one additional turn of the nut, assuming the pinion bearings were good before. Won't hurt to try, and if it doesn't, you'd be going back in for pinion bearings anyway.
When I do pinion seals, I mark the nut, pinion shaft and yoke all in a line, then count the exposed threads on the pinion shaft so I know How far the nut is run in.

 

No you cannot replace pinion bearings and use the quickie method of pinion nut tightening back to where it was with the old bearings.

With new bearings, I cannot recommend you do anything except remove the carrier and start over on the pinion bearing preload. As long as you used the same shim under the inner pinion bearing as before, you should be OK to skip full gear setup. But you still need to set pinion bearing preload properly. That means use a 1/4" drive beam style torque wrench to measure pinion bearing preload with incremental tightening (~1/16 turn once play is gone) of the pinion nut (use a new crush sleeve!). You want somewhere around 20-30 inch pounds preload on new bearings. If you go over, like 40in lbs, pull it back apart, new sleeve, start over. The current bearings are probably fine--chatter means too loose. I once tried just winging it, tightening the pinion nut until the chatter stopped. That lasted roughly 200 miles and then I was dealing with this:



Do it right, and then you can essentially forget about it for years.

 

He said he did only the pinion seal. Which is why I suspect he missed a turn on the pinion nut.

 

These rear ends have a crush sleeve, maybe all of you should do a search on what that is and how it affects things, preload and shims aren't applicable here unless modifications have taken place.

 

I read his post as he replaced the pinion bearings as well as the differential (side) bearings, in which case GoinBoarding is 100% correct. You need to start over with a new crush sleeve and an inch-lb deflection type torque wrench. You will have to pull the carrier again though.

If you don't get it exactly right, the gears won't last and you'll end up having to do a complete rebuild.

 

Thanks for the feedback guys. Very much appreciated.

To clarify - in the differential I only replaced the pinion seal.

I may have confused things by pointing out that I was also replacing the both sets of rear wheel bearings and seals.

I did as Heavy outlined -- marked the nut, shaft and yoke and counted the threads. That being said, did NOT write down the number of threads (as suggested in online instructions) knowing with my super memory I would remember the number. One would think I would have learned long ago to write things down.

I will try the additional tightening approach first. The bearing looked/felt fine and, as mentioned originally, there was no side play prior to disassembly.

 

The additional tightening did the trick. Now I'll pray it didn't simply mask a problem and I end up with something like GoinBoarding showed us.

Thanks again for your help fellas. It'll be nice to drive my old truck again.

What I didn't mention in my original post is that the wheel bearing fell out in pieces. When it failed the rollers got jammed inside the hub to the extent it locked up the wheel and I had to be towed. Fortunately, this happened within a mile of home the day after we had returned from our daughters house which is 130 miles away. I was very fortunate.

 

I see, I misunderstood you and thought you replaced all bearings in the axle. You're probably good to go. Glad it was fairly easy.

 

If the pinion nut was removed, the crush sleeve was disturbed meaning that the bearing preload was changed. It might be ok for a long time, but then it might not. The crush sleeve has to exert pressure in order to maintain preload, what has happened here is you removed nut, yoke, seal and then tightened again, and just sandwiched the bearing and crush sleeve in there, with no regard as to how tight the bearing or crush sleeve are. I hope it works, good luck to you.

 

I had that happen with the full-floating Dana 60 in my '85 F-250HD. Except I was about 80 miles from home, going 50 mph on a 2-lane blacktop coming home from a hunting trip when the left rear locked up. I was able to back up and free it up, then drove home, expecting it to lock up again at any time (it never did). Not a fun trip!