I have noticed a fluid stain on the rear cover of the rear end. Upon closer inspection, the leak IS NOT coming from this area but is coming from the area between the universal joint and "hog nose" portion of the read end. Is this the YOKE? Has a seal gone bad here? I'm far from being a backyard mechanic. Would appreciate any suggestions as to where this fluid is leaking from, what is causing it, and what type of expense am I looking at in getting it reparied. I have this worse case scenario that the whole read end has to be removed to replace whatever seal has gone bad.

This vechile is a 2000 Ford F-150 4X4 Lariat, 5.4 liter, w/80k miles.

Again, any help is appreciated.

Thanks,

Mike

 

Welcome ! Call your local mechanic of choice and ask them for the total price to replace your pinion seal. It's a common problem and repair.

 

Indeed, it's the pinion seal that leaks. The oil runs out onto the back side fo the yoke, and that's what flings it all over the underside of the truck.

Not generally an expensive or difficult part to replace.

-Joe

 

Ive replaced a few pinion seals and am set up to do it correctly.My advice to you is,if you've never done one leave it to a pro.They will most likely charge you $100.00 - $125.00.BTW,ide take it to a shop that does "just" suspension work only or differentials only!

 

As a side note to this correct diagnosis by those previous posts , have the u-joint checked as well since Ford is consistently cheap in the u-joint area and these are the common cause. The u-joint begins to fail and rotates out of balance, causing the pinion seal to fail and leak. It's a really cheap fix if you already have the pinion apart (~$30) and will save you money in the end, since if it is the u-joint, you won't have to replace another pinion seal before you find out it was the u-joint. Make sure you get a heavy duty, GREASEABLE u-joint from your local parts store, stock u-joints were not greaseable, do not last and should be replaced.