Hey Group, I've got a 91 Jeep Cherokee with a 4.0 engine. Can anyone tell me if this is a one piece knock-in seal or is it the old two piece type where you have to drop the pan and the last rear main cap. Just trying to plan my weekend out. Thanks, Charles
But, way over 50% of the 'rear main' leaks turn out to be just a valve cover leak. The engine is tilted and when the valve cover leaks it runs right straight down the back imitating a rear main seal leak.
To check, get the engine running and wipe a clean rag behind the head, if you find oil, you have likely found the main leak.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT'sErv>
Two piece, drop the pan & rear main cap. I replaced my rear main seal a couple of months ago. Wasn't as bad a job as I expected.
88 CherokeeRick
I sure wish you guys were right about the valve cover gasket, but I replaced it a couple of months ago. This engine has 188,000 miles on it and it's definitely the rear main...flowing like the Exxon Valdez. Do I absolutely have to pull the tranny or can I snake it in with the trans in place? Thanks for your replies! Charles
The only advice of my mothers that I actually follow!
It's a two piece seal. It is relatively easy to replace, but seldom fails.
The actual problem is most likely the valve cover gasket. Would you like to know how I know? I hope not.
The engine is raised on the front. Oil is pumped to the top, and flows down the pushrods back to the crankcase to start over again. While the oil is flowing down, it also flows to the back. The gasket likes to break in the back. The gasket is about 1/4" thick. The hole that results when the gasket breaks is however much the gasket shrinks wneh it breaks x 1/4" (or the actual thickness of the gasket). Oil flows out this hole, runs down the back of the motor and off the bottom of the bellhousing. It looks just like a rear main. Pull the valve cover first.
Trust us, wipe first.
If the rear main really needs to be replaced, it's easy. Well in relative terms, it's easy. You may need to remove a motor mount and a cross member to get the pan off. But, after you get the pan off, remove the rear bearing journal and push the seal out of the upper journal. There is no need to pull the trans off.
The rear main seal consists of a two-piece neoprene single lip seal. Correct installation of the seal is required for leak-free engine operation.
Drain the oil Remove starter motor Remove pan Remove pan side gaskets Remove all sludge and throughly clean gasket surfaces Remove rear main bearing cap Remove and discard lower seal Clean bearing cal throroughly Loosen remaining bearing caps Use brass drift and hammer to remove upper half of seal.
This is from my FSM for 1981 Jeep V8 engines. It seems to apply to both the
304 and the 360.I just hit 280,000 Km today and check the oil since the last oil change (3000 km). Still the same....No oil leak and not burning. i Just love my I6 , Am i the only one in this case ? i got it a 237,000 Km and was well taken care off.
"Jeff Strickland" a écrit dans le message de news: snipped-for-privacy@corp.supernews.com...
That's a nice article.... very well done job...
Hope i dont have to do any of this in my life.
Pat
"L.W. ("ßill") Hughes III" a écrit dans le message de news: snipped-for-privacy@cox.net...
My Cherokee had 296,000 miles on it when I changed the rear main seal. It was hard and brittle when removed. I used a piece of brass (gas) welding rod to get old seal to break free from its bond to the block.
I put Vasaline on the new seal to slide the upper half in above crank and it slid in easier than I thought it would. The pan removal was the hardest part of the job. I disconnected the drag link at the bellcrank on the steering box to get enough steer linkage clearance to get pan out under convertor housing. I removed the starter and pried on ring gear to rotate crankshaft and pushed seal around the crankshaft with my fingers to get upper seal slid in. I didn't remove the transmission.
Replacing the seal stopped the oil leak. I too had already went the valve cover gasket route.
It was real warm out when I replaced mine, but I'm in Fla. Hope it's not too cold where your at or you have a warm place to work.
I'll hit 300,000 mi. before the weekend.
Good luck,
Rick
Snow...
Just a FYI, but the valve covers have a 'really' sneaky habit of backing off the bolts after a new gasket. So if you didn't glue the gasket in, it sure is worth another wipe and just a finger test on the bolts. I will bet you find the bolts loose.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT'sErv>
We have over 300K km and same deal. If it is down a liter, it is overdue for a change....
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT'sPatrick wrote:
So it would be sufficient to re-torque the valve cover bolts? Or would you have to R&R the valve cover gasket?
-Bill (remove "botizer" to reply via email)
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