Symptoms
Oil dripping from where the engine meets the transmission, with no obvious leak above it. Hagerty lists rear main leaks as a common 360 fault.
The fix, step by step
- Rule out the valve covers, intake and oil-pressure sender first, because oil runs downhill to the bellhousing.
- Then drain the oil, support the engine, and drop the oil pan; on a full-size Jeep, front axle and crossmember clearance make this the hard part.
- Remove the rear main cap, pull both seal halves, clean the grooves, install the new seal, refit the cap to the factory torque spec, and refit the pan with a new gasket.
- Fill and check for leaks after a heat cycle.
Tools & part numbers
- Floor jack and stands
- engine support
- torque wrench
- seal pick
- RTV per seal instructions
- factory service 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 ↗
1989 Grand Wagoneer engine gaskets and seals catalogRockAuto ↗
Grand Wagoneer oil pan gasket searchTeam Grand Wagoneer ↗
Hunting a used or discontinued part? Search eBay Motors for Jeep Grand Wagoneer (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.