Help me ID this leak

[TerryMason]

I noticed what appears to be oil leaking from where my transmission mates with my engine. Not much is leaking - probably two drops within 4 hours.

A buddy at work said that it's the rear main seal, which means I need to pull the transmission. What do you guys think?

 

[SteelHeadz]

I would agree with the leaking rear main seal ONLY IF the rear of the cylinder head is dry from a leaking valve cover gasket. Rarely in some occasions that a head gasket would also leak in the rear corner of the engine. I would verify the 2 areas in question before i condemn the rear main seal. If it is in fact the rear main seal, you don't have to remove the transmission. The seal is a 2 piece viton seal with a single lip. Here's the service procedure outlined from the FSM.

Replace the upper and lower seal halves as a unit to ensure leak-free operation.

1. Remove transmission inspection cover.
2. Remove oil pan.
3. Remove main bearing cap brace.
4. Remove rear main bearing cap (No.7).
5. Push upper seal out of the groove. Ensure that the crankshaft and seal groove are not damaged.
6. Remove lower half of the seal from the bearing cap.

Oil pan Removal

REMOVAL

1. Disconnect negative cable from battery.
2. Raise the vehicle.
3. Remove the oil pan drain plug and drain the engine oil.
4. Disconnect the exhaust pipe at the exhaust manifold.
5. Disconnect the exhaust hanger at the catalytic converter and lower the pipe.
6. Remove the starter motor. Remove the engine flywheel and transmission torque converter housing access cover.
7. If equipped with an oil level sensor, disconnect the sensor.
8. Position a jack stand directly under the engine vibration damper.
9. Place a piece of wood (2 x 2) between the jack stand and the engine vibration damper.
10. Remove the engine mount through bolts.
11. Using the jack stand, raise the engine until adequate clearance is obtained to remove the oil pan.
12. Remove transmission oil cooling lines (if equipped) and oxygen sensor wiring supports that are attached to the oil pan studs.
13. Remove the oil pan bolts and studs. Carefully slide the oil pan and gasket to the rear. If equipped with an oil level sensor, take care not to damage the sensor.

I hope this helps.

 

[Team Twisted Off Road]

If it's a one pice rear main than yes and drop the oil pan...... if its a 2 pice than you can just drop the oil pan and fix it that way..anyway you do it it's tight.....thats my 2 cents..

 

[xjmarc]

It's a jeep it's supposed to leak.

 

[Crazy4diesels]

Mikey's directions are good - I've done it this way before. I'll just add that when you tap out the upper half be sure to use something that will not scratch the crankshaft. I was able to get it started with a small dowell (wood) and then pull it the rest of the way out with pliers. Best of luck - John

 

[yo momma yj]

there may be a "freeze plug" on the end of the cam also...another possible oil leak, but it's most likely a main crank seal.

verify that it's motor oil and not smelly trans gear lube?