Front differential leak, should I just redo the RTV?

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LJcooljay

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Hello all,
Long-term reader first-time poster.

I have never had leaks around the differential covers when changing the diff fluid on my 2005 LJ.
I feel like I do it by the book, razor blade & wire brush off the old RTV, then bead new RTV around the pan n leave for 24 hours before refilling.

Anyways,
Two weeks ago I changed the front inner axle seals. This fixed the leak dripping out the axle ends on the knuckle, though now I have a slight collection of fluid dripping off the bottom of the diff cover. The cover was on there pretty tight from a lot of RTV the last time I changed the fluid. I wonder if I subconsciously put too little on the pan this most recent time and this is why it's leaking?
After noticing the leak I read on here that I shouldn't fill the diff to the fill hole so I sucked a little out last week & cleaned everything but it is still leaking a bit from somewhere.
I'm most likely going to just reseal again this weekend with more black RTV but curious if anyone has any thoughts.

One weird thing I'm curious if it has to do with anything.
If you look in the images below, all the bolt heads have numbers stamped & a ridge on them except the one I put on the bottom bolt hole. this one is smooth. just curious if that is my issue.

Also, I'm pretty certain this is diff fluid. way too clean for engine oil & don't see any coolant leaks.

IMG_1573.JPG


IMG_1572.JPG


IMG_1576.JPG
 
LJcooljay said:
Hello all,
Long-term reader first-time poster.

I have never had leaks around the differential covers when changing the diff fluid on my 2005 LJ.
I feel like I do it by the book, razor blade & wire brush off the old RTV, then bead new RTV around the pan n leave for 24 hours before refilling.

Anyways,
Two weeks ago I changed the front inner axle seals. This fixed the leak dripping out the axle ends on the knuckle, though now I have a slight collection of fluid dripping off the bottom of the diff cover. The cover was on there pretty tight from a lot of RTV the last time I changed the fluid. I wonder if I subconsciously put too little on the pan this most recent time and this is why it's leaking?
After noticing the leak I read on here that I shouldn't fill the diff to the fill hole so I sucked a little out last week & cleaned everything but it is still leaking a bit from somewhere.
I'm most likely going to just reseal again this weekend with more black RTV but curious if anyone has any thoughts.

One weird thing I'm curious if it has to do with anything.
If you look in the images below, all the bolt heads have numbers stamped & a ridge on them except the one I put on the bottom bolt hole. this one is smooth. just curious if that is my issue.

Also, I'm pretty certain this is diff fluid. way too clean for engine oil & don't see any coolant leaks.

View attachment 519760

View attachment 519761

View attachment 519762
Click to expand...

Sometimes after changing several times enough old silicone can get in the bottom of the hole that when combine with a little new silicone the bolt bottoms out and interferes with getting it as tight as it should be. It will feel tight but a little squishy if that makes sense. Not a bad idea to pick out the collected silicone from the bottom of hole with an awl prior to resealing.
 
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Definitely get a lube locker gasket. It appears to be leaking from the bolt hole and not the gasket area. I’d try pulling that bolt and wrap some Teflon tape on it, and then stick it back in there. See what happens. Or back that bolt off a little, apply some RTV around the hole/bolt, then tighten the bolt back up.
 
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If you offroad and smash the diff cover hard enough the lubelocker will fail.

Also, looks like the bottom bolt just has a ton of oil/dirt caked onto the top of it.
 
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I've also switched over to lube lockers and am never going back. I know with a gasket it's important not to over torque the bolts, not sure if that's a thing with RTV.
 
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tworley said:
If you offroad and smash the diff cover hard enough the lubelocker will fail.

Also, looks like the bottom bolt just has a ton of oil/dirt caked onto the top of it.
Click to expand...

If you offroad and smash the diff cover hard enough will the RTV option fail?

I completely get showing there is a weakness with Lubelocker, but I'm curious if the same break point is there with the other option?
 
Use The Right Stuff 1-Minute Gasket Maker and forego the 24-hour waiting period.
 
cpwolf said:
If you offroad and smash the diff cover hard enough will the RTV option fail?

I completely get showing there is a weakness with Lubelocker, but I'm curious if the same break point is there with the other option?
Click to expand...

The lubelockers are great--not trying to discredit them at all. I ran one for years and it held up really well even after removing/installing multiple times. I still have and use one for the rear cover. But if the diff cover is hit often and hard enough, the gasket can break/bend. The RTV at least has the ability to deform and bounce back during a hard hit. How much force to change that...I honestly have no idea. There are several of us who have had lubelockers on the front though and have gone back to RTV due to leaks.
 
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tworley said:
The lubelockers are great--not trying to discredit them at all. I ran one for years and it held up really well even after removing/installing multiple times. I still have and use one for the rear cover. But if the diff cover is hit often and hard enough, the gasket can break/bend. The RTV at least has the ability to deform and bounce back during a hard hit. How much force to change that...I honestly have no idea. There are several of us who have had lubelockers on the front though and have gone back to RTV due to leaks.
Click to expand...

All good, I was just gauging. That's good info, didn't think you were, appreciate the experience background.
 
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I have had the same experience as Tworley with the lube lockers. If you are planning on being in the rocks, stick with the RTV. If not the lube locker works great.
 
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Actual squish-out:
1713559903339.png

Well under 90%. :)

I also used the recommended two-step process. Finger tightened the bolts until the RTV squeezed out a little, evenly all around, and let it vulcanize for an hour. Then torqued the bolts, squeezing out more of course, and waited 24 hours before adding lube.
 
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