Rear main seal replacement

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rtadams89
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Rear main seal replacement

Post by rtadams89 » Wed Jan 27, 2021 9:57 pm

I have a leaking rear main seal. For anyone that has replaced the seal, did you go with a NOS seal or just make your own with gasket maker?


Chuck W.
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Re: Rear main seal replacement

Post by Chuck W. » Thu Jan 28, 2021 8:53 am

AO-42 2-cylinder?
Not sure what you are asking, the front and rear crankshaft seals are rubber-lip metal-backed seals, not something you can make with gasket maker. I would not recommend NOS seals, they are usually hard and brittle. Contact John Emery and get fresh, new production seals and the new gaskets, too.

rtadams89
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Re: Rear main seal replacement

Post by rtadams89 » Wed Mar 17, 2021 3:37 pm

I thought this leak went away for a bit, but it's now back and worse. The oil is collecting at and dripping from the bottom of the flange where the engine and transmission mate. Is the gasket there 2520-918-6194?

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nickd
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Re: Rear main seal replacement

Post by nickd » Wed Mar 17, 2021 7:40 pm

There is a gasket between the transmission bell housing and the engine. If there is an oil leak at that location it could be the rear engine seal if it’s motor oil. If it’s 90WT oil it’s the seal in the transmission. Either way the repair will require removing and reinstalling the engine. Once the engine is out, I would replace both. Check the manuals for further detailed information.
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Re: Rear main seal replacement

Post by Chuck W. » Sun Mar 21, 2021 12:04 pm

If you are leaking oil between the engine and the bell housing, you first need to pull the bell housing drain plug and see if there is any oil in the housing. Should be dry or at least only a few drops. If you get much oil, you need to determine if it is engine oil or transmission oil. Most likely transmission oil from leaking axle seals. It's a real pain to change the seals, the ring gear must be removed as the inner seal is installed from the ring gear side.
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