changing rear end fluid in 99 Cobra with IRS?

I need to change a gasket in my rear end and i'm not sure how to drain and add fluid to it.. also whats the best fluid out there?

Drain it you take the cover off. Put cover back on fill plug is on top half-tranny side of diff housing. Redline/Royal purple and Ford friction modifier for the Trac-loc.

Yeah, it might get a little messy.

ok thanks guys.. this sounds like its gonna be a pain in my ass..

It's really not that bad of a job just a little messy like Craig said.

ok, i bought some sealer, because the IRS rear end doesn't use traditional gaskets.. kinda gay but oh well.. and i bought this stuff called lucas which was highly recommended.. do i need anything to insert the fluid since its on top of the rear end? do i need a hose or something? how much rear end fluid should i put in. is it a fill all the way type deal?

Did you goto a Ford Dealer to get your gasket? Cause I know that Ford does not list a gasket for the 8.8 solid-rear they say just use RTV Silicone. But Fel-Pro definetly makes a gasket for it, so maybe they do the same for the IRS.... RTV alone is fine I just like to use both whenever possible.

Next did you goto a Ford dealer and get thier Friction Modifier? If not do so it's like 4 bucks it helps the clutches in the diff.

I usually just use a rubber hose and squeeze the oil in the diff case. Fill it till it starts to come out the fill hole.

There is a special tool for filling rear ends.. its kinda like a caulk gun, its just a metal tube with a piston inside, a hose on one end and a rod/handle stickin out the other attached to the piston.. stick it into your bottle of diff fluid, suck it up, stick it in the fill hole, and push it out. Takes some time and muscle, since the diff fluid is so thick. You don't really need the tool I suppose, but it makes things easier.

There is a special tool for filling rear ends.. its kinda like a caulk gun, its just a metal tube with a piston inside, a hose on one end and a rod/handle stickin out the other attached to the piston.. stick it into your bottle of diff fluid, suck it up, stick it in the fill hole, and push it out. Takes some time and muscle, since the diff fluid is so thick. You don't really need the tool I suppose, but it makes things easier.


I'm tired just reading that.... I'll just use my rubber tube LoL