OK, I noticed a "whine" coming from the rear of my 2000 F150. Thinking this might be a wheel bearing issue I jacked up the rear and tried to rock the tires. They didn't "rock" at all but there was a whole 1/2" or so of play in and out. i.e. the whole tire could pretty easily move in and out a whole 1/2". Is this normal?

Seems abnormal to me, but I'm not clear that it's a bearing issue. Looking at the diagram for the wheel bearings it doesn't appear that they're needle bearings so they really shouldn't have an effect on this, right? The drum brakes seem like they wouldn't really mind if the wheel shifted back and forth, so maybe this is normal with drum brakes??

One other thing to note, there's apparently a leak in my rear differential as I can see fluid dripping out of the cover.

 

That is not normal. I would get that checked out right away before it causes damage. There is something going on for sure.

 

OK, seems it may have been a bit of an exaggeration to say it moves by 1/2". I looked at it again and it's about 3/16" to 1/4" of play. Still way more than I think it should be. I'm thinking it's something wrong in the differential now because it seems the axle and the wheel hub are all one solid piece of steel.

 

Hmmm. Are you all sure that there's not supposed to be this 3/16" play? I've got the thing apart and it appears that there's no real design that would prevent this play. The end of the axle seems to actually bottom into the pinion shaft which stops the wheel from moving too far inboard. The "C-Clip" prevents the axle from moving too far outboard. It doesn't appear that theres really anything there that would eliminate the play that I'm seeing..

Also, the top and bottom spider gears are really futzed up. Lots of pitting and gouging on the teeth. Should these be replaced or is a certain amount of gouging to be expected?

I took some pictures of the gears so you can see the chipping on them:



Also, one last question. How hard should it be to spin the transmission with the axles removed and the transmission in neutral? I would think it would spin pretty easy, but I have to wedge a screwdriver under an ABS gear tooth to get it to move. Is that normal?

 

Seems like this has become a differential problem and not a wheel problem. Can a mod move this thread to the "other powertrain" forum?