Rear Main Seal Issues
Thread Starter
Seasoned Member


Joined: Dec 2019
Posts: 257
Likes: 11
From: Los Angeles
Year: 1992
Model: Cherokee (XJ)
Thread Starter
Seasoned Member


Joined: Dec 2019
Posts: 257
Likes: 11
From: Los Angeles
Year: 1992
Model: Cherokee (XJ)
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Joined: Dec 2016
Posts: 3,539
Likes: 416
From: SoCal
Year: 1987
Model: Cherokee (XJ)
Engine: 4.0
Dont use assembly lube on the bolts. I would rather see you use engine oil. Bolt holes do not need to be free of oil. Just clean the threads and add more oil.
Thread Starter
Seasoned Member


Joined: Dec 2019
Posts: 257
Likes: 11
From: Los Angeles
Year: 1992
Model: Cherokee (XJ)
what kind of grease should I use on the bolts, dont want to use oil. Wanna do it the right way. And should I soak both the lower and upper half in dish soap?
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Joined: Sep 2017
Posts: 1,560
Likes: 307
From: MO
Year: 1996
Model: Cherokee (XJ)
Engine: 4.0
Just the upper, I did oil. The lower one you will use a light amount of RTV so it needs to be dry and free of oil.
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Joined: Dec 2016
Posts: 3,539
Likes: 416
From: SoCal
Year: 1987
Model: Cherokee (XJ)
Engine: 4.0
Yes! Small amount of rtv on each corner! Do not forget that. And by small I mean really small amount. I use soap over oil since soap is easier to get off and removes all oil = better and cleaner surface to apply the rtv.
Thread Starter
Seasoned Member


Joined: Dec 2019
Posts: 257
Likes: 11
From: Los Angeles
Year: 1992
Model: Cherokee (XJ)
thanks so much! And for the threads, before applying grease, should I use parts cleaner on them so they are clean and dry?
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Joined: Dec 2016
Posts: 3,539
Likes: 416
From: SoCal
Year: 1987
Model: Cherokee (XJ)
Engine: 4.0
No problem! And nope, dont worry about getting everything off the threads. Just wipe them off with a rag and then apply the arp stuff I posted. Main thing to make sure is that the threads are clean and dont have any junk in them.
Thread Starter
Seasoned Member


Joined: Dec 2019
Posts: 257
Likes: 11
From: Los Angeles
Year: 1992
Model: Cherokee (XJ)
Okay. Is it harmful if I do clean the bolts with cleaner prior to using the grease? Also The new oil pump I bought came with a gasket. Does the surface on the block where the oil pump gasket goes need to be dry/free of oil?
Thread Starter
Seasoned Member


Joined: Dec 2019
Posts: 257
Likes: 11
From: Los Angeles
Year: 1992
Model: Cherokee (XJ)
Can you recommend another brand for the threads grease? I cant find ARP near me. Is permatex thread sealant more or less the same thing? Also, why do you use soap on the upper seal and not grease?
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Joined: Dec 2016
Posts: 3,539
Likes: 416
From: SoCal
Year: 1987
Model: Cherokee (XJ)
Engine: 4.0
Get a lube that says it has "moly" in it. Your typical parts store should have a couple different options. Do not use thread sealant!
I like soap better because once the seal is in, you need to get all the oil back off it so that the RTV will stick to it. Soap is a lot easier to get off than oil. Either way will work though. Just make sure you get both the top and bottom of the seal clean and dry before applying the RTV.
I like soap better because once the seal is in, you need to get all the oil back off it so that the RTV will stick to it. Soap is a lot easier to get off than oil. Either way will work though. Just make sure you get both the top and bottom of the seal clean and dry before applying the RTV.
Thread Starter
Seasoned Member


Joined: Dec 2019
Posts: 257
Likes: 11
From: Los Angeles
Year: 1992
Model: Cherokee (XJ)
Get a lube that says it has "moly" in it. Your typical parts store should have a couple different options. Do not use thread sealant!
I like soap better because once the seal is in, you need to get all the oil back off it so that the RTV will stick to it. Soap is a lot easier to get off than oil. Either way will work though. Just make sure you get both the top and bottom of the seal clean and dry before applying the RTV.
I like soap better because once the seal is in, you need to get all the oil back off it so that the RTV will stick to it. Soap is a lot easier to get off than oil. Either way will work though. Just make sure you get both the top and bottom of the seal clean and dry before applying the RTV.
Thread Starter
Seasoned Member


Joined: Dec 2019
Posts: 257
Likes: 11
From: Los Angeles
Year: 1992
Model: Cherokee (XJ)
Dry between the bearing and rod (clean with brake clean and make sure there is no lint leftover. Wiping it with your finger works good). Assembly lube between bearing and crank. And dont listen to bignuge. It's not going to blow up. It would have already if there was an issue.


