Rear Differential Fluid

[eric jones]

I have a leak in the rear differential and I am planning on installing a gasket to remedy the problem (ford tech said they came without a gasket, thus the leak). What fluid is recommended and do you need any friction reducing additive?

[WI Fordguy]

I never use gaskets on differentials, even if they come with them in the first place. And they don't leak, I always use rtv black silicon and you need to let it set up for at least an hour before you add fluid. And yes you'll need a friction modifier unless you use a synthetic that already has it in there. 80W90 is the weight.

[RoyLPita]

I never use gaskets on differentials, even if they come with them in the first place. And they don't leak, I always use rtv black silicon and you need to let it set up for at least an hour before you add fluid. And yes you'll need a friction modifier unless you use a synthetic that already has it in there. 80W90 is the weight.

I would use 75w140 with a bottle of friction modifier.

+1 on the RTV use. BTW, have the tech that services the rear pull the axels out to see if they are not wearing out. I did that for piece of mind.

[RF Overlord]

I would use 75w140 with a bottle of friction modifier.^^^What Brian said^^^

Ford no longer recommends 80W-90 conventional for the Panther.

When I replaced the axles in Phoebe, I used a Victor Reinz gasket and it doesn't leak.

[fastblackmerc]

Redline 75w140 - no additive needed.

Use either a gasket or an "RTV" gasket. If using RTV to make the gasket follow the directions on the tube.

[MOTOWN]

i used rtv black when i rebuilt my carrier, no need for a gasket

[WI Fordguy]

Sorry, 75w140 is right. I had old Ford truck rear end in my head from work.

[LeoVampire]

I have a leak in the rear differential and I am planning on installing a gasket to remedy the problem (ford tech said they came without a gasket, thus the leak). What fluid is recommended and do you need any friction reducing additive?

There is a new gasket out there that is reusable for rear ends. Lubelocker

No sealer needed totally self sealing and can not be crushed.

I put it on my Marauder when I did the new cover. So far no leaks and no problems since last years installation.

http://www.bluecollarperformance.com/llr-f880.html

24660

[ctrlraven]

I used the gasket that came with my TA Performance diff cover and it leaked. Last time the cover was off to replace some bearings I had SmokdMercRauder use RTV and zero leaks now.

[eric jones]

Thanks Guys!