put RTV on diff or cover, which side?

[g6civcx]

Have a little debate at the shop.

Guy A says you should run the RTV on the diff housing then put the cover on. He says it's a stronger seal.

Guy B says you should run the RTV on the cover and then put the cover on. He says it's easier to work on the cover than under the car.

Who has the better approach?

[ericcastro]

i would vote for the diff.

Of course, we do our diffs out of the car, so its not to big of a difference. But i always just feel more secure putting rtv on the main part of the car, then putting little covers and stuff onto that.

I know with my oil pan, i put it on the block first.
with my timing chain cover, i did it on the block first.


With it on the cover, as you go in for the big line up, you could bump something or rub along something and the rtv could be wiped off an area, and you wouldnt know.
(i think its more unlikely that the cover would rub it off the diff)

Also, its not as messy. having to move peices around that have glues and sealants on them can get messy and pick up pieces of metal shavings and shit on the move.

[Def]

It doesn't matter what side the form-in-place gasket is placed on, as long as the surfaces are VERY clean, the bond will be the same strength.

The important thing to do with RTV is to NOT torque the bolts immediately. You just want them finger snug, then let the RTV setup for about 1-2 hrs, then torque the cover. Wait 1 day, then fill with fluid. People always immediately torque and you eventually get a little bit of metal to metal contact with allows for a slight bit of leakage if things aren't 100% flat.

[g6civcx]

It doesn't matter what side the form-in-place gasket is placed on, as long as the surfaces are VERY clean, the bond will be the same strength.

This is what I said. We're splitting hair at this point, although I hear what he said about moving the cover around and shifting the RTV.

The important thing to do with RTV is to NOT torque the bolts immediately. You just want them finger snug, then let the RTV setup for about 1-2 hrs, then torque the cover. Wait 1 day, then fill with fluid. People always immediately torque and you eventually get a little bit of metal to metal contact with allows for a slight bit of leakage if things aren't 100% flat.

I agree.

[Def]

If the parts are together when you get movement, then it doesn't matter which one you applied it to.

I tend to put RTV on the removeable part(diff cover, water pump etc.). If there's a groove machined for more RTV retention it's usually on the replaceable part, so it serves as a nice guide.

[Chrischeezer]

Is this a serious question?
better check the fsm
HAHAHA

[Mister.E]

im with Castro on this one. i always remove the diff from the car whenever im working on it so its easier just to put it on the diff casing itself then slap the cover on. like the guy above said, though, if both surfaces are clean it doesnt make a damn bit of difference which side you apply the RTV to first.

[g6civcx]

Is this a serious question?
better check the fsm
HAHAHA

Yes, this is a serious question. I already know that the FSM says to put RTV on the cover.

Guy A is an ASE Master technician with 50+ years of experience in building race car. Guy B is a Nissan factory-trained technician with about 20 years of race car fabrication experience.

This is just a discussion. If you don't want to discuss then it's fine.

[yokotavia]

this thread is serious fail or your just really bored

its all personally preference, your gonna smear it either way

boom

[g6civcx]

Do you know how many people I spoonfeed a day on here? It's not often that I ask something, but every time I ask something it's always a battle.

All you need to say is A, B, or doesn't matter. There is really no need to say anything.

[Tearlessj]

I gatta say, it can't be that important. I had a welded blow at the last event. I had to swap covers to use a new diff. I got some 5 minute dry time RTV from autozone. Threw that bitch on there, tightened it right away, and drove off in the next 10 minutes. Doesn't leak at all. There was also still some paper gasket that I was too lazy to get off still on there.

[dynamicck]

The person who's right is... the owner of the car. Reason being it's his car, and if there is a problem, it's his problem.

Usually if I'm helping someone with their car. If I think my opinion is right, i'll tell him what I think, but I let him decide. Because if something happens, he's the one who chose the decision.

[MELLO*SOS]

I think it doesn't matter which side at all - the end result is the same, it's just personal preference.

With that said I agree with Eric my preference is on the main/non-cover part. Reason is the RTV can touch something else during the lineup if you just put it on the cover.

I also squeeze the RTV out then use something to rake it flat into a uniform thickness layer. I think it helps reduce bubbles and pockets that might cause leaks later... Plus it gives me a chance to get rid of some excess that's going to squeeze out/into the part being sealed...

Good thread...