Oil Leak Around Bellhousing

Hey guys,

I have bad oil leak coming from around the bellhousing of my transmission. Ive had the Rear Main seal replaced and the oil pan gasket. Everything was done right. But still leaks oil kinda looks like its coming out the bottom opening of the bellhousing. It all started this past monday, took it to get fixed because the oil was leaking so bad as I going down the road the oil would hit my exhaust pipe and smoke like crazy. The mechanic said he would fix it so I went back the next day. Drive it about 15 miles, and the leak starts again. So I take it back to him and tell him to fix it of course no charge, he said its the oil pan gasket and that he must have put it on wrong. So he says he will fix it. Come back the next day and drive it again about 15-20 miles and it does the same thing again. Take it back, and this time he tells me he might have gotten the rear main seal in backwards. So says he will fix it again, free of charge of course. Come back the next day and does the same damn thing again leak. But he said he had gotten the seal in right and even put a new one it, he said he made sure he put sealent on the main bearing cap as well. Sorry for the long post everyone but its really starting to irritate me. Ive checked everything, oil pressure sending unit, and made sure it wasnt leaking down from anywhere else. It's definately coming from the opening in the bellhousing or in front of it from the main seal, I cant really tell.

BTW That mechanic will never work on my 92 jeep cherokee again
Any info would be helpful.

Matt

XJJeepinMatt said:

Hey guys,

BTW That mechanic will never work on my 92 jeep cherokee again
Any info would be helpful.

Matt

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Hey Matt, sounds like your mechanic is very considerate and trying to resolve the problem - go easy on him!

You might want to check the back of the valve cover for leaks. This is often mistaken for rear main seal leaks. Also, check the oil filter mount, they're notorious leakers - replace the o-rings.
-Brian

I agree with Brian....the mechanic has been going the extra mile...you won't find that very often, the guy has gone WAY in the hole on this job trying to make it right...if it aint leaking from the main seal or the oil pan, the list gets short...oil filter adapter (very common) or valve cover (very common) there is an EXTREMELY REMOTE possibility that it could be the cam bore plug in the block (this would be highly unusual, since it would have to have rusted thru from the outside). since you mentioned the oil pressure sender, i'm assuming you don't have a mechanical oil pressure gage...the line to a mechanical gage can easily wear thru and leak, usually where it goes behind the motor to get across the firewall. Good luck

I would say it is the valve cover gasket. BTW your mech. went way past the call of duty.

when the o-rings on my oil filter housing went bad, i had a lot of oil around the bell housing. it was tought to tell where it was coming from. is your filter dry?

2kxjcu said:

when the o-rings on my oil filter housing went bad, i had a lot of oil around the bell housing. it was tought to tell where it was coming from. is your filter dry?

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I vote O-rings inside your oil filter housing. When they leak the oil hits the lip of the oil pan then works its way back to the 1/2 circle where the rear main is.

Take the Jeep a self serve car wash, use the "tire cleaner" feature and give it the business right around the oil filter, all the way back to where the starter, and finally back by the rear main. The "tire cleaner" feature is usually low pressure so you shouldn't have anything come unhooked while using it. After it's had time to break down the oil and grim, rinse the area. Be careful with the water pressure.

After that I usually pull out an old towel and dry off the areas in question. Drive it home and inspect with a flashlight. You'll probably see the trail from the oil filter to the back of the oil pan.

Yesterday I took it to a car wash, cleaned the engine and around bellhouse and oil pan and let it dry. I started it up, and sat underneath and watched it. The leak is coming from the inside of the bellhousing from the looks of it. My buddy said its def not the rear main, but im stumped guys. The leak starts out slow then gets faster as u warm up the jeep. I have some pics at the following links http://www.geocities.com/mattsxjjeep/oil1.jpg
http://www.geocities.com/mattsxjjeep/oil2.jpg
http://www.geocities.com/mattsxjjeep/oil3.jpg

Sorry bout the crappy quality they were taken with a picture phone. Like I said Ive cleaned everything thoroughly and its definately coming from the opening at the bellhousing. I called the mechanic and told him thanks for the help. The rear main is not leaking so he did help after all, but im still leaking motor oil from the bellhousing and dont know what it could be. I checked the O-rings on the oil filter, no leakage and not trail so its def not that.

Matt

After it dryed, was/is there any oil on the block under the oil filter. It would also show a little trail of oil along the lip of the oil pan...moving to the back of the oil pan...then as you drive the oil blows back on to that shield...and you get that drip...the same drip I use to have. <major run on sentence>

I seriously thought my newly replaced rear main was bad also...it turned out to be the o-rings. Now that I am thinkging about it again my rear main probably wasn't even bad. :twak:

Did you remove the dust cover to confirm for sure it is coming from inside the bellhousing? If it is in fact coming from inside the bellhousing...it has to be either the rear seal, cam bore plug, or the main oil galley plug....the cam bore plug is a cup plug similar to a "freeze plug"....the oil galley plug is a screwed in pipe plug...it would be so wierd for either of them to leak, unless the motor was just rebuilt and they were improperly installed then...

Hey guys,

I didnt see any oil trail coming from around the oil filter. Tomorrow Im gonna try replacing the Valve Cover Gasket , along with the o-rings for the oil filter, and see if that helps. I will keep you updated. The motor is the original and just passed 170,000 miles. I havent had any problems and runs great, except i cant drive it now because of this leak. It leaks onto the exhaust that crosses over underneath the bellhousing cause the oil to burn and smoke, and smells up the cab pretty good as well.

Matt

Depending on how the rear slinger and drainage channel is designed (and I've had my XJ for like a whole week so I'm not sure - if it was a John Deere or Caterpiller I could tell you), a rear main bearing with way too much clearance can put a lot of oil pressure behind a rear main seal and blow it lickety-split. That's a long shot though. The miles you have on the rig wouldn't normally be enough to think about worn main bearings, and an outright failure would probably be making some noise (and giving you a very low oil pressure reading). It sounds like the pan needs to come off gain so I'd go ahead and Plastigage that bearing.

I have the same problem as you. I took all my oil pressure hoses off the top of the engine an replaced them with new ones. If they start getting plugged up (very usual), they will start forcing oil out of the weakest seal on your engine (which, coincidently just happens to be the rear mail seal, most of the time). That doesn't mean your rear mail seal is bad and needs to be replaced, just means you need to either clean or replace the hoses in the engine. I upgraded my hoses to a little bit bigger size and switched to actual hose (instead of those plastic hoses they come stock with). That seemed to help quite a bit for me. But I didn't catch on to that for a while and it ended up breaking my rear main seal, so now I need to replace that and then everything should be all good.