RTV Bead or Smear?

robert92679 · 01-03-2007, 10:01 PM

Just wondering, when you install differential covers, do you leave the RTV in a solid bead, or smear it around?

Do you think there are any benefits to one method or the other? Or, does it really not matter?

**paultyler** · 01-03-2007, 10:10 PM

You are suppossed to put down a bead. When you put the cover on it will spread out. If you smear you may get a leak.

RockRunner85 · 01-03-2007, 10:14 PM

I run about a 1/4 inch bead all the way around the cover. I go around each bolt hole, even though you really only need to go around on the inside the bolt hole.

Make sure you read the directions. Most have an hour wait time. If you do not follow the directions it will leak!!!

Most say after running the bead bolt cover in place finger tight. Let sit an hour. Then torque down bolts and fill.

The one time I was in a hurry I just tightened the bolts and filled the diff. It starting leaking 5k later.

BlueFlame · 01-03-2007, 10:19 PM

It takes RTV a heck of a lot longer than an hour to set.
Agree on just snug it down and then wait, but I usually wait overnight to torque then fill.
On the other hand, I've never seen a shop wait, and they seem to seal fine...

kizer · 01-03-2007, 10:24 PM

I place a bead and then smear it around to insure the entire surface has a thin coat. I torque all the bolts just a little bit less than spec then again at spec. Ive yet to wait any longer than 10minutes and Ive never had a leak.

Its never failed and since it works for me Im going to continue my method. Is it the correct method? Sounds like it isn't, but it speaks for it self.

**Rocky529** · 01-03-2007, 10:32 PM

Leave it in a bead, and avoid placing the bead around your holes in the cover. Gently place the cover against the differential, and hand thread all the bolts. Once you crank them down, the RTV should not smear onto the threads of the bolts and a little RTV should "ooze" out creating a seal.

Michael_K · 01-03-2007, 11:01 PM

Bead, otherwise you are risking bubbles.

Michael K.

alvinl · 01-03-2007, 11:21 PM

I have always used a bead and run it around all bolt holes. I do 1 diff, snug the bolts up finger tight then let it dry while I do the other diff. Or let them both sit while changing the tranny and transfer case fluid. Then torque down and fill. So I give them some time to dry, but not overly long. I have yet to have one leak. But now that i've said that, I bet my last diff job leaks...

Materdaddy · 01-04-2007, 01:56 AM

Bead, Bead, Bead!!!

UCTJ · 01-04-2007, 02:22 AM

Put a nice even bead...not too thick it will just spooge out anyway. But a nice even bead, never had a diff on me.

Brew461 · 01-04-2007, 03:06 AM

Quote:

Originally Posted by UCTJ

Put a nice even bead...not too thick it will just spooge out anyway. But a nice even bead, never had a diff on me.

Is it a concern if the RTV "spooges" a little to the inside and makes it into the carrier?

Jeremy99 · 01-04-2007, 04:21 AM

I have reusable gaskets now, but in the past I would apply a bead and spread it evenly across the sealing surface. I would then wait 3-5 mins for the sealant to "film" over (allow the exposed layer to begin to set), then I would install the cover and finger tighten the bolts. I have never allowed time before I torque down the bolts, not that it was a race to tighten them or anything. I never had any leaks. Seems like I read that method on the back of a tube of sealant one time.

Michael_K · 01-04-2007, 06:23 AM

Quote:

Originally Posted by brew461

Is it a concern if the RTV "spooges" a little to the inside and makes it into the carrier?

Unless you got something sensitive like limited slip clutch, I would not worry about RTV damaging high strength steel.

Michael K.

PeteC · 01-04-2007, 08:16 AM

Bead.......always a bead.

Let the pressure of tightening the metal surfaces together spread the material. That is the way this stuff was designed to work. The pressures will put it where it needs to go. If you smear it on in a thin coat you may not have enough in a certain spot to fill all voids. Even cork gaskets had some give to fill voids. Actually, I was raised to use a thin bead of RTV on cork gaskets just to insure a first time seal. Overkill maybe, but hell, my dad learned that as an aircraft mechanic.

Anyway, that's how I roll.

p.s. For those that use the smear method, if it works for you, cool.

BlueFlame · 01-04-2007, 10:40 AM

I think the answer to getting a leak free seal is Clean Surfaces.
I don't think beading, smearing, paper gaskets or rubber gaskets matters so much, but good clean surfaces for the sealing medium to seal to is important - even more so with silicone than with gaskets.

View Poll Results: On a diff. cover, do you leave the RTV in a bead, or smear it around?
Leave it in a bead	65	85.53%
Spread it around, like butter on toast.	11	14.47%
Voters: 76. You may not vote on this poll

01-03-2007, 10:24 PM	#5
kizer Registered User Join Date: Dec 2003 Location: Marysville Wa. North of Seattle Posts: 1,601 Profile Gallery Classifieds My Jeeps	I place a bead and then smear it around to insure the entire surface has a thin coat. I torque all the bolts just a little bit less than spec then again at spec. Ive yet to wait any longer than 10minutes and Ive never had a leak. Its never failed and since it works for me Im going to continue my method. Is it the correct method? Sounds like it isn't, but it speaks for it self. __________________ Links4Jeeps.com 1600+ Write-ups, and more My Writeups \| My Heap

01-03-2007, 11:01 PM	#7
Michael_K Registered User Join Date: Jul 2004 Location: ATL, GA Posts: 982 Profile Gallery Classifieds My Jeeps	Bead, otherwise you are risking bubbles. Michael K. __________________ DailyDrivenTJ.com JUST For Jeep TJ Owners Around the World!