Okay to use a Felpro gasket & RTV on rear diff cover?

 

Better to use only sealant, like Ford recommends, and the way the axle was originally built.

 

Use a gasket, it is better than sealant. If you don't prep the surface perfectly, follow directions, it will leak. The reason sealant was originally used is strictly economics, it is cheaper.

 

yes it is okay.

 

When I was a kid, I worked part time in a tranny shop. My jobs included scraping mating surfaces, running parts though the cleaner, and emptying the trash...

That job also included diff cover re-install after we'd drain 'em for whatever reason... We did it every way there, depending on who was on duty... Gasket, RTV, and sometimes both combined.

I didn't ever see any leaks come back to the shop from any of those methods.

 

Check out lube locker. When I’m ready to change my diff oil that’s what I’m planning on using.

 

Well I had a gasket & I had the sealer (RTV ) . I used them both making a 1/8th inch bead on diff & cover. I let it cure for 48 hours, added oil, drove around & checked it twice for NO leaks.

 

No leaks for now. Generally gaskets and RTV together shouldn't be done. Go check with Felpro and I would bet you will get the same recommendation. Time will tell.

 

Have heard antidotal stories it’s ok to refill diff after an hour of dry time on RTV. Instructions for Permatex grey gear oil gasket maker 81182 are to install bolts hand tight and wait an hour before tightening to torque. And then wait 24 hours before refilling. Had I realized that before pulling my cover I’d have bought a gasket instead of RTV!

 

The word is "anecdotal". RightStuff can be filled immediately (one minute, according to its label), but this has been drying overnight while I wait for the friction modifier to arrive.

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I'm also swapping front sway bar bushings, adding an ATF cooler, doing some other mods, so I'm in no rush.