AMC 4.2 rear main seal oil leak

[yjfever]

Dear fellows: My YJ Jeep is leaking oil even with new oil pan gasket correctly installed. After removing rear main Bearing, found that the two ribs or rims indicated in red were broken in both block sides, probably trying to remove rear oil seal that goes over the crankshaft. Any ideas on how to put some kind of seal there? We tried with high temp silicone, but it didn't work. Any advise will be greatly appreciated. Thank you guys...the broken lips are the ones at the end of the 2 red lines, inside the circle, both sides.

 

[Chris]

Dear fellows: My YJ Jeep is leaking oil even with new oil pan gasket correctly installed. After removing rear main Bearing, found that the two ribs or rims indicated in red were broken in both block sides, probably trying to remove rear oil seal that goes over the crankshaft. Any ideas on how to put some kind of seal there? We tried with high temp silicone, but it didn't work. Any advise will be greatly appreciated. Thank you guys...the broken lips are the ones at the end of the 2 red lines, inside the circle, both sides.

View attachment 123661

Sorry to hear about your issue with the rear main seal leak. Those broken lips can definitely cause a headache! When it comes to repairs in that area, silicone alone often isn't enough to create a reliable seal, especially under high pressure. Here are a few suggestions you might find helpful:

• Repair Epoxy: Consider using a high-strength epoxy designed for engine components. This can help fill in the broken areas and create a solid base for the seal. Just make sure it's rated for high temperatures and can withstand oil exposure.
• Alternative Seal Design: If you can't repair the block, you might want to explore the option of using an external oil seal or a lip seal that can accommodate the damage. Some aftermarket solutions might help achieve a better seal despite the broken lips.
• Machining: If you know a good machine shop, having the block machined to a slightly larger diameter could allow for a new lip for the seal to fit into. This is a more involved fix but could solve the problem permanently.
• Oil Stop Leak Additives: While not a permanent fix, some users have had success with oil stop leak products. They can help swell seals in certain conditions, but keep in mind it's more of a band-aid solution.

Make sure to clean the area thoroughly before applying any materials, and consider whether the situation might need a more intensive repair if the leak persists. Good luck, and keep us posted on how it goes!

 

[yjfever]

Chris: Thank you for your input trying to help me. Your alternatives are all inclusive, I believe, and firstly will try the Epoxy suggestion in hope that it will fix the damage. Reading on this for a while I have seen many difficult situations solved by forum members. Would you to go deeper on the outside seal. How to do it and how to keep it fixed so it stops the leak. Thank you so much...best regards...