cherokeemtnman

87 cherokee, i just put sythetic oil "royal purple" and now my rear main seal is leaking, if i put regular oil you think that will stop it? just how hard is it to replace, reading the manual it says to drop oil pan and rear main cap and honestly i really dont want to get into all that.....

liftedjeepxj

Same thing basically happened to me. I put Lucas oil additive in and my rear main just leaked about a frisbee worth of oil day one.

I was told the rear main is a bit easier that they claim it to be. Supposedly it's a two piece seal and when you take the oil pan off there should be a small cover with two bolts. Take that off and get the bottom piece out and lightly tap one side of the top piece until it makes it's way around to pull out. Install is the opposite.

I haven't done it myself, but XJ is know to leak there (as well as oil pan/valve cover/ and seal @ harm balancer) so I searched about 5 write ups on changing a rear main.

Feel free to correct me if I'm wrong!

Cool Hand Luke

I think I heard somewhere that synthetic oils wont soak into the seals n stuff like real oil does, might cause the seals to shrink, and leak? don't know tho, I'm not a mechanic... yet lol makes sense to me tho. is this right?

1991Jeep_Man

Hardly. That couldn't be further from the the truth. GOOD (not generic) synthetic oils, like Mobil 1 [I use it], Castrol, etc. use additives and such that help restore old seals, plus synthetics are more refined and just perform an overall better job.

s14unimog

I would love someone to confirm the first two posts. I've got to drop my transmission for a rebuild and need to replace my rear main. I would love to know what to expect in regards to that seal.

cherokeemtnman

well i know you have to drop oil pan and the rear main bearing from what ive read and just like above post you tap one side until the other side comes poking out, im sure theres detailed post about doing this but my question is whats the probablility if i drain sythetic and install regular oil do you think the oil will stop leaking or is the damage done? i just replaced clutch couple of weekends ago and I really really not in the mood to be dropping oil pans right now....

xPlover24x

why dont you use the search? i used it and found everything i needed for when i did mine. its a VERY simple concept. google it dude. its literally everywhere

cherokeemtnman

why dont you READ i know how to change it im asking do you think if i put regular oil back in will it stop....its soo easy to be an *** but takes alittle effort to be helpfull

SamSissine2

Why don't you not even comment.

I understand what you are saying but seriously your comment adds nothing.

If you would like to search for the OP and post a link to another thread that you thought answers his question, then that would be helpful otherwise your input like that can be left out...

xPlover24x

http://jeepin.com/features/rearmain


that was easy

not even 5 mins on google

SamSissine2

Royal Purple or dare I say any Synthetic is not going to cause you leaks. If you drain it and put a thicker oil in there synthetic or conventional you may slow it down but I would not advise doing that damage to your engine to slow down a fixable leak.

Synthetics will do a great job of cleaning up so with that sometimes you may see a leak start since you had sludge plugging that leak before but I'd rather have the leak then gunk. Synthetics are not harmful for your seals from what I have read and should do a great job of protecting them if they are already not damaged.

cherokeemtnman

R u retarded? The question was not how to replace...

s14unimog

yeah man I hear ya, I don't know if any of use can really guarantee that would work. You might as well just give it a shot b/c its the cheapest/easiest option before pulling the pan. Right?

Jeepability

i just changed mine. take the oil pan down and take the two bolts loose and tap the top seal out

vandelden21

i know this really doesnt apply to this post but when do rear mains normally go out in the 4.0's? im at 185k i have no idea if mines been done all i know is i have the h.o. swap done and the only oil i leak is out of the valve covers. should i just do the rear main before 200k? or do they normally last awhile.