Symptoms
Oil dripping from the joint between the engine and bellhousing.
The fix, step by step
- Following Jeep's 1973 service-manual procedure (via IFSJA): drain the oil and remove the pan.
- Remove the rear main cap and discard the lower seal half, loosen the other caps and tap out the upper half with a brass drift.
- Oil the crank, fit the new upper half with the lip facing the front of the engine, put sealant only on the lower half's end tabs, and seat it in the cap.
- Seal the cap's chamfered edges, torque the caps to spec and refit the pan with new gaskets.
- Always replace both halves together.
Tools & part numbers
- Brass drift
- torque wrench
- Permatex No. 2 or equivalent
- two-piece rear main seal
- oil pan gasket set
Where to buy the parts
CJ rear main seals (by engine)Quadratec ↗Amazon ↗
Oil filter, 1979 CJ-5 4.2LRockAuto ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Jeep CJ-5 parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.