Rear Differential Cover - to RTV or not RTV the gasket?

[2010gmcyukon]

I plan to replace my rear differential cover when I change the fluid (it's pretty rusty). I don't know the condition or type of the existing gasket so I will plan to replace it as well. I've seen mixed information about using RTV on the gasket. Does anyone have advice on what's recommended?

 

[alpinecrick]

I'm thinking yours still has the 10 bolt diff....

Felpro gasket, dress both sides of the gasket with Permatex Gear Oil RTV. Or the black RTV. After installing the gasket let it sit most of the day or overnight before filling with gear oil.

The latest friction modifiers in various lubes/oils are getting past gaskets more readily. That's why Permatex came out with these specific RTV's. The trick is to let the RTV become mostly cured before refiling with oil.

 

[2010gmcyukon]

I'm thinking yours still has the 10 bolt diff....

Felpro gasket, dress both sides of the gasket with Permatex Gear Oil RTV. Or the black RTV. After installing the gasket let it sit most of the day or overnight before filling with gear oil.

The latest friction modifiers in various lubes/oils are getting past gaskets more readily. That's why Permatex came out with these specific RTV's. The trick is to let the RTV become mostly cured before refiling with oil.

Correct, it is the 10 bolt. That makes sense letting it cure before filling with oil. I appreciate the feedback!

 

[swathdiver]

We bought the Fel-Pro gasket and RTV when changing our fluid for the first time. Read posts here and decided to try use the old gasket and no RTV. A few months later we did an axle seal and took the cover off again, cleaned it, put it back on, without RTV. The Fel-Pro stayed in the garage where it was eventually destroyed. The original is still doing its job 28K miles and near 1000 hours later since the last repair.

If your original gasket looks good, you can re-use it. It certainly looks better than the blue Fel-Pro replacement. To each his own.

 

[HiHoeSilver]

I'm a fan of the Lubelocker gaskets. Used one on my trans pan. Very nice.

 

[mizzouguy]

I'm with @alpinecrick. Thats the exact way I do it, a thin coating on both sides of the felpro paper gasket so that it doesn't poop out everywhere. One thing to note, I do flatten out the cover around the bolt holes each time. If someone over-tightened them in the past it can make the cover flex a little, causing the mating surface to not be perfectly flat. Most people don't take the time and are just fine anyway. If you go the lubelocker route, those are sweet!!! Just never had the time to order one.

 

[Rocket Man]

It depends on the gasket. Some like the lubelocker are designed to not use rtv, while the cheap ones are designed to use it. You can always opt to use rtv with the lubelocker type which defeats the purpose and I doubt it can be reused after.

 

[SnowDrifter]

Rtv

Gasket

Pick one, IMO. If you rtv a gasket you now have effectively 3 gaskets on there, each of which can fail, with the advantages of none. Rtv being cheap, and a hard gasket minimizing labor time for future maintenance.

I've used rubber, paper, and impregnated gaskets(lube locker) all without rtv. None have yet to leak.

I generally prefer a hard gasket on account of easy future maintenance and no fussing with dry time or residual oil on the surface. But that's purely a personal preference. There are benefits and drawbacks to each. Just pick one and go with it