Engine seal

Engine seal

Scout1067

Old Time Jeeper
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Location
Germany
Vehicle(s)
1981 CJ7, 258, T176, D300, D30 front diff, AMC 20 rear diff, Weber Carburetor, BDS 2.5" lift
I got up under my Jeep yesterday to do an oil change. First thing I noticed was the engine oil was about a quart low, it was good the last time I checked it right after Thanksgiving. When I got under it it looks like engine oil is dripping out of the bell housing. I first thought it was from the transmission but both that and transfer we're full when I checked.
My guess is blown rear main seal. The only way I know to check a main seal is drop the tranny and look. Is there another way to tell if I am right? I don't want to drop the tranny if I don't need to.
Here are some pictures of the underside.
I didn't think to get pics until I had wiped off the bottom of the bell housing but it had a drop on it, what we would have called a Class II leak in the army.
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Have you made sure it's not coming from up above like the valve cover and running down the back of the engine?
 
^^^:agree:
Once you are certain that it's motor oil and not transmission oil, (looks like you already did) you should be able to pull the inspection cover off the bell housing and tell. If the inside of the bell is full of oil, and it's not coming from above, you are right. The rear main seal is leaking.
 
What weight oil? How many miles on the engine?
Check to be sure your PCV valve is clean.
CK your oil at every gas up or at least once a month.
LG
 
Its possible that only the lower portion of the oil seal needs replacing. This would involve only removing the oil pan and bearing cap. This worked for me.
 
What weight oil? How many miles on the engine?
Check to be sure your PCV valve is clean.
CK your oil at every gas up or at least once a month.
LG


I am running 5w-30 because it gets pretty cold here in the winter.

The PCV had a little froth on it and so did the oil cap when I took it off.

As to how many miles are on the engine, I have absolutely no clue. I think it is still the original engine but the odometer read 10,418km when I bought it last year and I assume it has rolled over at least once in 37 years.

I will get some picks of the valve cover and try to get to a bay next monday to check inside the bell housing as Bass recommends.
 
Here are some pictures. It almost looks like oil is coming out of the breather filter.

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That foam is caused by condensation inside the engine. It WILL clog the PCV valve and breathers. That can/will lead to over pressure within the engine block.
You are not letting the engine run long enough to 'burn' off this condensation..........
What is the temp. range(degrees)you see there?
LG

P.S. Move the wire loom up and away from the back of the valve cover in pic#2.
 
You ar also missing a bolt in your oil pan that can cause the pan to come loose and leak oil. I would check all of your bolts and replace the missing one. I typically put a dab of lock tight on the bolts to help keep them from backing out

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You ar also missing a bolt in your oil pan that can cause the pan to come loose and leak oil. I would check all of your bolts and replace the missing one. I typically put a dab of lock tight on the bolts to help keep them from backing out

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Had me going for a second there. I took that pic right after I drained the oil. I started to freak and went and crawled around under the Jeep in the 20's til I looked at the picture and saw you were talking about the drain plug.
 
That foam is caused by condensation inside the engine. It WILL clog the PCV valve and breathers. That can/will lead to over pressure within the engine block.
You are not letting the engine run long enough to 'burn' off this condensation..........
What is the temp. range(degrees)you see there?
LG

P.S. Move the wire loom up and away from the back of the valve cover in pic#2.

That could be as I pretty much only drive to work and back and that is a twenty minute drive. Lately the temps have been highs around freezing with lows in the teens and twenties.
 
Had me going for a second there. I took that pic right after I drained the oil. I started to freak and went and crawled around under the Jeep in the 20's til I looked at the picture and saw you were talking about the drain plug.
My bad there is a green spot on your one bolt and when I saw it I thought it was an empty hole with the gasket showing through

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