232 Rear main seal

I just bought a 78 cj5 with a 232 inline 6. The engine is leaking oil from the rear main area. Has anyone dropped the pan and changed the rear main seal before? Is it a 2 piece seal? How much of a pain in the butt was it?

 

I have not done it on a 232/258, but I have on other cars. Mechanically, it's not difficult. The process is a pain though - a lot of wrenching lying on your back. Be sure to wear safety glasses. You must have a torque wrench that will do 80 ft-lb.

Jeeps are easy to work on in general, because they sit high, are relatively simple mechanically, and there's a lot of room around the engine. I assume you don't have the factory manual - you can refer to the '72 manual on www.c104.net or Trailforge - same engine, same process. The FSM has a step-by-step description.

Yes, it's a 2-piece seal.

 

I've not done a rear main seal on a 232/258, but I did do one on my 4.0 in my TJ. It was pretty easy and I was able to go it in my driveway. 4.0s use a 2 piece seal, so the same thing is probably available for a 232/258.

Drain and drop the oil pan. Remove the rear main. Push the upper half out of the block with a pick. Grease the new one with vasoline and slide it in the block. Make sure you look at the orientation of the old seal when you take it out, they have to go in facing a certain direction. Put the lower half in the main cap and reinstall the main cap. Torque the cap bolts, then reinstall the oil pan. Fill with engine oil of choice.

Pretty simple and I think it took me maybe an hour

 

NB the manual says you should loosen all the main caps - you may not have to. If you can slide the top half of the seal in without damage, then you can remove just the rear cap. A good brand of seal (Felpro) will have a 'supplementary' instruction sheet too. Won't tell you how to remove the pan or cap, but will advise about inserting the seal.