Symptoms
Oil dripping where the engine meets the transmission, with nothing wet above it.
The fix, step by step
- Rule out the valve covers, intake and oil-pressure sender first, because oil runs back to the bellhousing.
- Drain the oil and drop the pan; on a full-size Jeep the front axle and crossmember make this the hard part.
- Remove the rear main cap, roll out both seal halves, fit the new seal, refit the cap to factory torque, and refit the pan with a new gasket.
Tools & part numbers
- Floor jack and stands
- engine support
- torque wrench
- seal pick
- RTV per seal instructions
- factory manual for torque specs confirm in manual
Where to buy the parts
Rear main crankshaft oil seal, V8-360/401 1974–1991Team Grand Wagoneer ↗Amazon ↗
Rear main crankshaft oil seal, 4.2 L 1972–1988Team Grand Wagoneer ↗Amazon ↗
1979 Jeep Cherokee engine gaskets and seals catalogRockAuto ↗
Hunting a used or discontinued part? Search eBay Motors for Jeep Wagoneer & Cherokee (SJ) 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.