I started noticing that my rear differential was leaking from the front (where the drive shaft enters). This is an easy fix for anyone with this same common problem. If your truck has higher miles, you might as well replace the bearings as well since you will be right there...I only have 55K so all I did was the seal itself to stop the leak.

After you remove the 4 bolts for the driveshaft and the pinion nut (mark so you replace in the same position)...you see this

some fluid will seep out but nothing major....I added about a half quart after it was completed.

Used a flat head screwdriver and scribe to remove the seal


NEW SEAL GREASED AND INSTALLED...pain!


Button everything back up the way you found it and add some oil to the diff and VIOLA! no more leak.

During the process, we checked the bearings for play and there was barely any (if any at all) so we chose not to replace.

 

Good work. On my 03 I had a seal at the wheel go out. The sad thing was, it took me a little while to get around to changing it out, in the interum I made sure the rear end had oil in it. That synthetic oil cost about 3 times as much as the seal. Turned out only to be about an hour job and 5-8 dollar part LOL. Procrastination strikes again

 

Should of changed your diff oil while you were at it. That looks pretty nasty

 

I actually was planning on it...except my smart self forgot my oil at my house that morning...not a happy camper. That's the next project

 

thanks for the insight to it, noone had done a write up with pics like this atleast i didnt find one searching and now gives me the motivation to change mine out b/c my rear plate is leaking a little too. thanks alot man and i agree with changeing the rear diff oil lol a little off color.

 

Way I always do it is before removing pinion nut and yoke ...
... I take a punch and lightly but clearly mark the yoke, the nut, and the end of the pinion shaft all three and then make a count of visable threads and note it someplace clear.

This way I can put the yoke and nut back on the pinion shaft exactly as removed and no tiighter with 100% certainty ..... so I know I haven't added crush to the crush sleeve.

I would not change that front pinion bearing unless it was needed either 'cause then you've changed the elements in the stack and run the risk of changing that crush. Properly lubed and adjusted they'll last the life of most trucks.

Just because you are "there" is no reason to screw with what ain't broke.

If you over crush that sleeve you've changed bearing preload and likely shortened the life of the bearings. Only fix is a new sleeve and set up.

Edit added ... I use some medium strength Locktite on the threads.

 

*** I think you need to make this more visible ***

*** This is ridiculously important! ***

If one does NOT set the correct preload/crush, your bearings WILL wear out prematurely....


Hopefully this makes it a bit more obvious ;-)

 

Kind of how I looked at it.

I did add an edit.

You know, your old Mustang looks better now than my old buddy's black on black '74 Mach I did when brand new ..... hummmmm?

 

Heres a video to show people in person rather than walk through with pictures. But Yes the crush sleeves are a huge part to this

http://www.youtube.com/watch?v=HNkGd...F41EA&index=37

 

That's a great video! Thanks mhockey9090

My question is regarding the 2006 f150 rear diff.. can anyone tell me what size socket i need for the pinion nut? I want to be sure i've got all requried tools handy before i start this on my truck.

Thanks!