"Wrong" Rear Main Seal

M

Miller88

NAXJA Forum User
Location
Syracuse NY
Well - I've hit a point where I now think I am in way over my head. I have done RMSs before on older 4.0s. It is easy.

I tore into my 2000 to replace it's RMS and, I have the "Wingless" RMS.

From what I see from searching on google - there are many, many different sets of procedures. No two of which are the same. That concernes me.

I saw one where someone put RTV directly on the bearing surface !?!?!?!? ... another one says to install the seal 30* off (which kind of makes sens). And yet more saying that I need a special oil pan gasket - but other posts saying the oil pan gasket to use is the one which I already have.

There is also some sort of dealer-only special sealant to use? This is what someone put on the bearing surface I guess?

Help!
 
Bearing cap and block: The factory manual specifies using anaerobic sealer on the both the cap & block since at least 1997. Its just a thin/small amount on a diagonal from the edge of the cap to behind the seal. Think about it as a catch that would let any oil go towards the pan rather than drip out. I don't think you need to use the dealer stuff, Loctite and Permatex both sell anaerobic sealer.

RTV for the pan gasket: I put it in 6 locations. Four dabs at the bends around the bearing cap and front cover, and then where the front cover meets the block. The FSM points to 4 locations but when I looked closely at the old parts and signs of RTV the factory was putting it in 6.

Pan gasket: Nothing special here. The Victor-Reinz dealer made gaskets have "ears" where the gasket bends around the rear bearing cap. The Fel Pro one's don't. I use Fel Pro gaskets and put a bit more RTV where the ear would be. If you have the original gasket check it out.

Seal itself: Sure, some folks will offset it 30 degrees. Nothing says you need to and I didn't.

I've done it by the book on my 2 XJ's one a year ago and one a month or two ago. Nothing has blown up yet. I do coat the backside of the seal with dish soap & the lip with oil and then use the drinking straw method to guide it in with my finger.
 
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Mine didn't have the factory gasket. Someone had been in this engine - aftermarket oil pan gasket (which was sealed, but they forgot to tighten the bolts), the crank girdle had 2 lose bolts and there was an oil pump bolt in the oil pan. And the rear main bearing is very tired it appears.

I have the FelPro ... having a bit of a hard time imaging where the ears go ... but I can take another look at the FSM.

I looked at the procedure in the FSM and it makes sense. I will get an anaerobic sealer for the portion of the cap. It looks like the difference is I would not put any sealant on the surface where the two sides of the seal meet - correct?

I have done 4.0 RMS before, but it was the winged style. I Was going to do it exactly the same until I found out all sorts of weird stuff online.
 
The "ears" are around the rear bearing cap where it meets the block. If you look at the rear bearing cap you should be able to see where they'd be. I don't have a picture.

The anaerobic sealer will spread wherever it needs to go and if too much is used then it will find exits, either out towards the torque converter or towards the seal & crank snout which is not desirable. I just put a small amount where the FSM shows.

I don't think you need to be too worried about it, there are multiple ways to get a leak free RMS install.
 
Yeah - the last few I have done seemed to be without issue. I may have got a bit over nervous when I saw all sorts of strange stuff on how to do the newer style one haha. I'm heading to buy the correct seal on lunch and some anaerobic sealer.

I am a bit confused as to where to put the extra RTV for the Fel-Pro pan gasket.

Hopefully I can get it all back together tonight.
 
Just put it all the common places you'd put RTV on any gasket - where the gasket bends around a corner or where there's a seam. The ears are where the gasket bends around the crank bearing cap. You'd normally put a dab in there anyway, but without the ears just put in a little more. Since you've done it before and haven't had leaks you'll likely do this one just fine. I normally put the oil pan gasket to the block with studs and push it all into place around the rear bearing cap, front cover, etc. and then slide the oil pan over the studs and start putting in screws. Wondering if you do the same? I've found it helpful to use vibratite or RTV on the oil pan bolts because I had the ones in the front cover backing out causing it to sweat there (even though everything was torqued to spec).
 
The worst of my leak was the oil pan gasket - and as I found out, the bolts had backed almost completely out on the left rear of the pan. If I had not done this project now and put it off a month or two, they would probably be gone. I am afraid to use locktite on such a small bolt that is of low grade into a captive spot like the engine. I will probably just check frequently.

What I have done in the past is attach the gasket to the pan, then put the little plastic studs in then wrap the whole thing in a plastic bag and and jack the frame to get it back in to place. I haven't worked on a highway only jeep so they get pretty dirty underneath. I know there is an oil filter for a reason - but fell better doing this. then I wiggle it in place, drop it down a bit and put on the RTV then install the whole thing then run the bolts in.
 
Well had to unholy the other caps a bit to get the seal out. Do I have to tighten the other caps before putting the seal in or after ?

Any specific sequence ?

The only reason it's this hard is because it's my jeep
 
I would do it before. As with anything long, start in the middle and work towards the ends alternately (example: 4, 3, 5, 2, 6, 1, 7)
 
Well I'm done.

I'm going to figure out a way and it's going to a mechanic. Otherwise I'm going to just smash the windows out of it and set a brick on the gas pedal.

The new seal got started fine. and started to go in fine ... then it ripped halfway. And, of course, when I tried to pull it out the rubber ripped and now there is half a rear main seal stuck in it.

Why is everything such a challenge on this thing?
 
:peace:If you didn't put the pan back up yet, remove the bearing caps plus connecting rod nuts to drop your crank. Put another RMS half on and bolt it up as usual. I've done a couple of these and it is "drudgery". I'll have to redo my pan gasket again because I didn't refit the dang girdle, stroked engine, of course. The sealant I've used is MOPAR for Maintenance Gasket maker which is red, says compatible with aluminum on tube.
 
Maybe you can use the other (bottom) half to drive out the remaining part? Use a fair amount of dish soap.

When you put another seal in, coat the lip with oil and the rest with dish soap.

Dawn works good, and cleans your hands really well. :) On the two I've done you can pretty much use your thumb to push upper half of the seal in. If it takes too much force I figure I haven't used enough dish soap. The straw method seems to help prevent getting things torn up but its the only way I've ever done it.
 
The hardest part last time I did this on another jeep was getting the oil pan off ... and cleaning the oil pan gasket mating surface!

It started going in fine, but once it got about halfway in , it just jammed. I'm afraid if I let the crank down anymore, it might have a bearing unseat in a race. Will see. Going to try to tighten up the crank bearing caps and remove the new bad seal..

The good news is if I buy a new seal, it's two identical pieces! haha.

It's going to sit for a few days, though. If need to cool down, otherwise therer is going to be a decent shape XJ that is missing the rear bearing cap and an oil pan in the local junkyard :)
 
I use brass punches to remove the upper half to the seal. If it won't come out on one side, try the other side. In my limited experience, hitting it on the second side after a bunch of whacks on the first side and it pops loose almost right away and you can pull it out with your fingers.
 
Got the old one out with a brass punch - but it's the new one that is stuck. It's 1/2 way in or so. Cant access it from the other side. Got it started with the shoehorn and it made it 1/2 way in and jammed. Won't go in or out a bit

I have the older upper half still. May be able to drive that around from the other side to see what happens.
 
Pliers wont' move it. I wonder if the crankshaft may have moved itself down and jammed it. I put it in by hand and it just jammed. I'm going to tighten the other main caps up then try to remove.

Have another victor/reinz seal coming in tomorrow - the good news is the pieces are identical!

I soaked it in engine oil along with lubing the back side of the seal itself with dish soap and putting a small bit in the seal area (yes, that's a no-no).
 
So, looking back - I think I could have got away with just applying anaerobic sealer to the bearing cap - there was none and the bearing cap and block have a bit of corrosion from water/mud working their way in.

I tightened up the crank main caps and it pulled right out by hand!

Have another V/R RMS on the way - that's two more tries!
 
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