FYI, I just got back from the dealership getting the parts to do this on my '04 XLT. My owner's manual spec'd 75W-90 and XL-7 friction mod for my LS 8.8, but the dealership showed me the ford pub that lists the updated spec as 75W-140 with XL-3 Friction mod.

BTW, for those that haven't done this yet, a quart of that gear oil is $18.. Ouch!

Awesome how-to, not really looking forward to doing this but at least now it's a DIY project and not big $$$ to the dealership.

 

First of all, I just wanted to say what a great how to thread this is. One of the most informative that I have seen. Secondly, I wanted to ask what the friction modifier is for?

Thanks,

Aaron

 

This post is going to be incredibly helpful for me. i'm doing my rear seals tomorrow, and saving myself a lot of money. wish me luck!

 

I know of a 2006 Ford 8.8 that started leaking the right rear axle at 139 miles. Brand new.

Warranty fix.

 

Thankfully I found this How To because I need to replace a leaking seal My first question is how can you know for sure that one of these bearings is making noise or needs to be replaced because it seems that there is a humming coming from the back but not sure. I know that there is a small whining noise that has started and can be heard when I'm on the gas but seems to go away when I take my foot off the gas and let it coast but as soon as I touch the gas even so slightly it will start back up and whine or sort of hum from the rear end.

 

Can someone tell me if the C-Clips come off easy and what do you use to get them off?

 

IIRC they just slide out. Been a while.

 

Thank you Stealth
Also does the 75W140 gear oil need to be the Motocraft brand?

 

Any brand will work. I used M/C and a bottle of friction modifier.

 

Freddy, That is exactly the noise that my 04 150 made when I was on the gas and my rear bearing was going out. In my opinion, it is most likely the bearing and you can probably confirm by looking for a leak where the axel housing meets the wheel flange. Once I pulled the wheel and rotor, there was grease all over the e-brake. That was another indicator that the bearing was going out/loosing grease, because my e-brake wasn't grabbing as well anymore.

 

I'm picking up the oil and modifier today and need to find a bearing puller and plan on doing this sooner than later.
When I changed my rear brakes last week I noticed one side was leaking and cleaned it all with brake cleaner and did the inside of the rim to. So far I've been checking to see if I can see it leaking again especially dripping on the rim when parked like before and it is always dry. I hope it doesn't mean there's no oil left in there to drip
But now after looking around I noticed an oil leak from the transfer case and it seems like it is coming from the shaft itself. Probably a seal in there to that is leaking.

 

How did the job go?

 

Thank you for the great write up and pictures showing how to replace the rear axle bearings and oil seals!

I have a 2003 automatic 2WD which I am in the process of doing these repairs to. The rear end is an 8.8 LS and I have just finished pulling off the pumpkin cover and drained the fluid.

Looking inside where the pinion shaft is, there is a metal "S" in front of the pinion shaft. Turning the rear end 180 degrees to the other opening, there is another "S" clip there also, once again in front of the pinion shaft.

I can not tell if these clips will just pull out, or if they are attached to anything.

Any ideas or help? Thanks

 

Just an additional note, none of the oil seals are leaking, but I do have a noise from the right rear, thats why I am doing the bearings and seals. Once I get the axle out, I'll see if I am going with bearings and seal, or the bearing repair kit with the integrated seal.

 

OK, I went back outside (108 today so far) and looked closer at those "S" clips that are there.

I was able to remove the pinion shaft bolt (5/16 head, rounded off from the Ford dealer when one of the oil seals was replaced under warranty years ago.) Thank goodness he skipped a step and didn't use Loc-Tite because I was able to break it loose with a 1/4 inch breaker bar and not round off the head completely. I'll be replacing that bolt!

I left those "S" clips in place and had enough room to push the axles in and remove the "C" clips. I used a pair of very long and thin needle nose pliers to reach in between the "S" clips and grab them. I had turned the axle to where the clip openings were facing away from me (after putting in the pinion shaft so as not to disturb the spider gears).

I actually think turning the axle was unnecessary because those "C" clips are not that snug of a fit on the axles, and I could have grabbed them and maneuvered them out without a problem. With the axles out, the "S" clips remained in place, and seem to help hold the spider gears in place if the pinion shaft is taken out.

I am going with a bearing repair kit because they look like they have more of a surface for the shaft to ride on. My axles are in pretty good shape, but I have 150000 miles on the truck.

I am checking the National Bearings RP6408 to make sure the bore is correct. My axle measures 1.619 where the bearings ride,but the National is listed as 1.399. I called the parts store and he said they would fit with no problem, that the listed 1.399 was incorrect. Other brands are listed at 1.622

I'll be taking my axle shaft with me to make sure they fit!

Hope this post helps someone else if they have any of the same questions or problems I had.