Rear Main Seal

[Gat'79]

I have an 86 that was swapped for the GM 2.8. I'm losing a quart every 5 days and I need to know exactly how to get at this seal. Is it like the 4.0 where I drop the oil pan and replace Or do I need to drop the Tranny to get at it first?

 

I'm not 100% sure it is the rear main seal also. Do I simply replace the oil pan gasket and then look for more leaks? 

[Green Mesa XJ]

Two styles in the gm 2.8.

If if the later styles it’s a one piece seal you can access from the back by dropping the transmission.

 

If it’s the older style it’s a two piece rubber seal, I think it is closer to the 4.0 but cat remember

 

 

Btw gm changed to the one piece seal in 1985, so you 1986 MJ should be a one piece design but if the motor has been swapped or gm sold amc a older block who knows what actually there.

 

Sent from my iPhone using Tapatalk Pro

 

[MJXJjeepguy]

Maybe if u know ur build date if u have a early date of 86 good chance to have 2 piece? 

[Gat'79]

Maybe if u know ur build date if u have a early date of 86 good chance to have 2 piece? 

It's an engine swap. Not sure of the build date, but if it is any indication the power steering pressure hose has the sensor on it.

Sent from my LYA-L29 using Tapatalk

[Green Mesa XJ]

The odds are it should be the one piece with bigger crank journals. But being a 2.8 god knows what’s actually in there


If you can get the block # on the passenger side under the are near the exhaust manifold , second location is on top under the bracket for the power steering on top of the motor.


Sent from my iPhone using Tapatalk Pro

[Jeep Driver]

It's a one piece seal, you'll need to drop the trans. 

 

If its leaking that badly it may be that he crank is so badly scored that a new seal won't last long. 

[LTZ_3]

My 86 2.5 was a one piece seal. 

[cruiser54]

the real issue with those motors was the back of the intake manifold leaking because they used no gaskets, but used rTV, on 2 flat surfaces. 

 

Be sure and check there first. 

[Green Mesa XJ]

Other big leak is the oil filter housing .

Have to lift the motor up and possibly remove engine mount


Sent from my iPhone using Tapatalk Pro

[Gat'79]

I'm going to get under there when my power steering pressure hose comes and I replace the steering gear box. Thank ya'll for giving me clues on where to look.

Sent from my LYA-L29 using Tapatalk