How hard would it be to change a pinion seal in a 8.8??mine is leaking and i dont want to pay $75 to have it changed..

 

Pulling the old seal out and hammering the new one in isn't that hard. But you've got to worry about getting the proper pinion bearing preload; whenever the pinion nut is loosened - like when taking it off to remove the pinion flange - the pinion bearing preload changes. If you don't get the preload right when going back together, at best you'll have some gear whine, and at worst you could destroy the pinion bearings and/or pinion gear.

 

thats what i was worried about.. do u have to go into the diff at all?? I have to pull the axle out anyways cause i have a leakin axle seal... as well.. any special tools needed??

 

Well, there's two different schools of thought on replacing pinion seals.

The proper method is to tear the axle down, replace the seal, install a new crush sleeve and put it all back together. This is because with the old crush sleeve in place, it's easy to get carried away and overtighten the pinion nut, putting way too much preload on the bearing. Also with the carrier and everything installed, you won't really get an accurate pinion bearing preload reading.

The way that you aren't supposed to do it is just by pulling the pinion flange off, pulling the old seal out/knocking the new one in and bolting it back together.

I've done it both ways, and the only way I'm really comfortable with is the first because it's kinda hard to get an accurate bearing preload reading with the carrier and all still installed in the axle.

 

It's not necessary to tear the axle down to do it right - the crush sleeve is easy to remove after pulling the pinion seal & outer bearing.

http://www.differentials.com/install.html
http://www.fordracingparts.com/downl...And-Pinion.pdf

For more info, click my black Bronco below & look in the 8.8" Axle album.

 

Illness95.
i also lost my pinion seal while driving cross country. smelled gear oil when i stopped to get gas. checked the level, and lost almost 1 quart!! i got a cheap seal, and forgot to use some rtv between the seal and housing. i had to change it out in the parking lot of a hotel!!
i had regeared it just a couple of weeks earlier, so figuring out how to pull the pinion seal in the parkin lot was easy.
my recommendation: before you pull the flange off, make a mark with a paint pen, or a scribe,as to where you can reference the position of the pinion nut on the pinion. when you re-tighten the pinion nut after you have changed the seal, make sure the alignment marks are dead on when you re-tighten the nut . this will get you pretty damn close to what the torque on the pinion bearings will be.
im still runnin my truck that way, 8000 miles later, no problems, no whine!
Oh yeah, Did i mention to use rtv on the seal before you put it in, or get one of those nice seals that already has some waxy stuff already on there.
Good Luck in whichever you decide, Just Givin some advice.