Gentlemen,

2000 Expedition, 4wd, 5.4l, auto, EB

Climbed underneath to double check my recent rear brake line replacement for leaks, and dang if the rear axle differential isn't leaking.

It's coming out the top - dripping down the face of the cover plate - last person in there sealed it with RTV and it's blown the seal at one of the upper bolts, so at least it stops leaking when stopped

I'll take a closer look, but pretty sure this is going to be a cover plate gasket replacement.

So, looks simple enough - remove cover, replace gasket, bolt cover back on, re-fill with fluid......except....darned if I can find a fill hole anywhere. Not on the cover, that's for sure. On the top of the diff housing there's an electrical connector that's bolted on the casing. Maybe under there? And what are those wires anyway?


Thanks.

 

I doubt you will find a gasket for it. Just clean both surfaces with brake clean. Check each bolt hole in the cover to be sure non of them are dimpled from being over torqued. If they are, hammer them flat on a block of wood.
Put a thin bead of RTV all the way around the opening AND all the way around each bolt hole. Then let it cure for a half hour or so before re-assembling it. Sung it up in a criss-cross patern and then tighten to spec (33 lb-ft) with a torque wrench.

Check the vent line to be sure it isn't plugged or it'll end up pushing out a leak again.

Look on the left front side, slightly above where the DS connects to the diff.

Rear axle speed sensor. Used by the ABS and the instrument cluster.

 

A new gasket was included with the new diff cover I got at Napa when I did my '01 a couple of months ago. I spent maybe 30 bucks.

 

Yep - just picked one up - brand new gasket included. Nice.

 

All very helpful. Thanks.

 

You can buy just the gasket from Advance Auto Parts. Be sure to clean off all of the RTV on the pan and the diff. FWIW, I use RTV and a gasket. At $20 a bottle of gear oil, I want to make sure there are no leaks. I would also recommend buying a cheap hand pump from Harbor Freight. It'll make life easier when refilling the dif.