Ford 7.5" rearend differential cover gasket

[phipplet]

My rear end is leaking....ha! What's the recommended differential cover gasket for replacement? (Manufacture / part number?) Also, when I replace the gear oil do I need to add the stinky additive?

Thanks...

3114

[Chalky]

i think originally they were just sealed with silicone but there is a gasket available. Check your local O'reilly's, Felpro make one, I can 't remember the number of the top of my head.

I wanna be like Mike:):):)

[DaveS]

The Felpro part number for the gasket is RDS55393. If you're running a true Ford limited slip, you'll need to add the Motorcraft friction modifier (aka stinky additive).

[phipplet]

The Felpro part number for the gasket is RDS55393. If you're running a true Ford limited slip, you'll need to add the Motorcraft friction modifier (aka stinky additive).

Thanks for the info! What gear oil do you recommend?

[DaveS]

I don't use anything fancy for the gear oil (stock setup). Napa 80s-85s-90 in the white pint (I think) bottle works well.

You might want to check to make sure your oil leak isn't from the pinion seal.

[KevinK]

The dealer used silicone when they serviced my bearings under warranty. Rockauto lists a gasket but shipping is close to $10.

[phipplet]

I don't use anything fancy for the gear oil (stock setup). Napa 80s-85s-90 in the white pint (I think) bottle works well.

You might want to check to make sure your oil leak isn't from the pinion seal.

Yes! I have a new pinion seal, going to replace all of it after the engine work is done. Thanks for the help!

[dznj]

The Felpro part number for the gasket is RDS55393. If you're running a true Ford limited slip, you'll need to add the Motorcraft friction modifier (aka stinky additive).

Confirming that this is the one I put on my car. I used Valvoline fluid in the rear. I added the modifier as well.

D

[MikeFleming]

I'll just leave this here.

The proper fill procedure for the rear diff housing is to add gear oil to the filler hole, with the axle level, until it will take no more (fill with gear oil to the bottom of the filler hole). Install the fill plug.

Remove the vent on the right side axle tube and add the friction modifier there. The vent also mounts the brake line adapter. A small funnel is most useful here.

Note that the rear housing is now slightly over-filled.

[phipplet]

I'll just leave this here.

The proper fill procedure for the rear diff housing is to add gear oil to the filler hole, with the axle level, until it will take no more (fill with gear oil to the bottom of the filler hole). Install the fill plug.

Remove the vent on the right side axle tube and add the friction modifier there. The vent also mounts the brake line adapter. A small funnel is most useful here.

Note that the rear housing is now slightly over-filled.

Thanks Mike!

[stockman1]

Used Felpro gasket suggested above, changed rear end oil with Lucas 80W-90, and LSD friction modifier. Took 1.5 quarts of oil and about 7 oz of LSD. I hate laying on my back and it was a bitch to fill but the rear end is now quiet around turns and on the straits.

[MikeFleming]

^
You're gonna have an almost new car there before long!!

[stockman1]

^
You're gonna have an almost new car there before long!!going to be my daily driver, commute is 2 miles each way.