i parked my truck at a steep angle left maybe sitting 1.5' lower than right and when i went to hop in the truck after, there was a big puddle of oil at the rear tire, i'v replaced the same axle seal before, was wondering if this is a common problem, and is it hard to fix yourself?, any info appriciated

 

are there better aftermarket seals and bearings than the ford ones? what does the friction modifier do, i'm sure the last time the seals were changed it WASN'T added, is that a big deal

 

I had to replace my right side rear axle seal at about 80k miles on my 2000F150Scab4x4. It's easy to do. Jack up the rear. Just remove the rear diff cover to drain the fluid. Remove the wheel. Push the axle in enough to remove the axle C-clip and pull out the axle. I don't remember for sure but I think you need to remove the large pin to get to the clip. A small bolt holds it in place. The using a screwdriver, pop out the existing seal. Inspect the bearing surface on the axle and inspect the bearing. Then install the new one. I used a piece of 2x4 to tap the seal back in. I put a paper towel over the seal first to keep any dirt from getting in the axle housing. Lubricate the seal surface with axle lube. Then push the axle back in and install the C-clip.
Reinstall the cover. I thought I had the sealing surface clean but when I used RTV for the sealer, it leaked afterwards. I would recommend using a gasket. I had to use 2 bottles of friction modifier to quieten my traction lok clutches instead of the recommended one bottle. The seal only cost about $3 so you may as well change both sides and I bought the seal from Ford. But, my old truck has 145k on it now and I don't think another seal has failed.

 

Do a search for axle seal replacement, there's an excellent write up with pics in here somewhere. I noticed my seal(s) were blown around 60k on my 04, unfortunately they went way before that and it cost me. I swapped out the whole rear except for the shafts. I now check the seals etc. every oil change. Good luck.

 

Do a search. Quinton did a thread with pictures and good directions on (How to change rear axle seals). The thread was dated 6-23-2007. Good luck.