Rear main seal

[Rick C]

Finally got sick of the oil dripping from the clutch drain hole and want to replace the rear main seal (at least I assume it's the rear main seal leaking).
How easy is this to do by just dropping the oil pan? Do I need to remove anything else???
Rick

[SOTVEN]

HUMMMM... I HOPE I AM WRONG, BUT IN ORDER TO CHANGE THE REAR MAIN IN PREETY MUCH EVERY ENGINE I KNOW, IS THE SAME PROCCEDURE AS CHANGING THE CLUTCH AND PRESSURE PLATE. THE TRANNY NEED TO BE PUSHED BACK. HENCE I NEVER GOT "TIRED" OF MY LEAKING REAR SEAL.

[Rick C]

Thats what I was thinking...the M38 needs the crank loostened to push the upper half of seal out. Was hoping there was an easier way.

[M37UK]

AFAIK its an easy operation, as Charles is sending me a new rear seal for my truck he will hopefully jump in and answer your question.

[MSeriesRebuild]

Most M37 engines have the split seal. Remove the pan and rear main bearing cap. Loosen the 2 intermediate bearing caps a little. This allows the crank to drop slightly and enough to push the upper seal half out and reinsert the new half. The bottom half is on the bearing cap. No need to pull the trans. Some very early engines have a bolt on flange type seal; this is tough to replace without removing the flywheel because of tight access. I have done it with the flywheel installed, but to be honest it's worth the extra trouble to remove trans, clutch, and flywheel to replace this type.

[Rick C]

Thanks Charles. Thats how I handled the M38....figured they were similar.
Rick

[SOTVEN]

I AM SO GLAD I WAS WRONG!!

[dwayneski]

I have a '53 withh 33000 miile on it and have been driving about 3 weeks now. I had a small leak in the oil pan gasket so i replaced it but now i have oil leaking in th rear of the engine. i remove the the clutch pan ant the plate between the trans and engine, ran the engine but nothng appeares to be leaking. after it leti it sit awhile then i have oil on the floor.

[MSeriesRebuild]

I have a '53 withh 33000 miile on it and have been driving about 3 weeks now. I had a small leak in the oil pan gasket so i replaced it but now i have oil leaking in th rear of the engine. i remove the the clutch pan ant the plate between the trans and engine, ran the engine but nothng appeares to be leaking. after it leti it sit awhile then i have oil on the floor.

Most likely scenerio is the rear main seal is leaking with the oil being picked up by the flange on the crank and slung outward by centrifical force. What you see dripping after the fact is the oil that was slung out as it runs to the lowest point and drips off a while later. Sounds like the leak is minor, check the crankcase vent tube that runs from the oil fill tube to the air cleaner elbow, be sure it is in place and not stopped up. Without free crankcase venting, oil will be forced past even a new rear seal.

[dwayneski]

The vent tube was gunked up pretty bad so i cleaned then put engine cleaner on the engine then i went to the car was to clean the oil up. then i left it in the garage to dry then i checked it after dinner and know can see the oil dripping from the seal.......thank

[dwayneski]

Some very early engines have a bolt on flange type seal; this is tough to replace without removing the flywheel because of tight access. I have done it with the flywheel installed, but to be honest it's worth the extra trouble to remove trans, clutch, and flywheel to replace this type

i have a 53 would any one know what type i have
Is their a access hole on the back of the engine? what about the front access?

[MSeriesRebuild]

Some very early engines have a bolt on flange type seal; this is tough to replace without removing the flywheel because of tight access. I have done it with the flywheel installed, but to be honest it's worth the extra trouble to remove trans, clutch, and flywheel to replace this type

i have a 53 would any one know what type i have
Is their a access hole on the back of the engine? what about the front access?

If the engine is the original to your '53, it should have the 2-piece type push-in type. The bolt on type is typically found on 40's model engines. You can tell easily; you will see 3 bolts in behind the flywheel holding each seal half if you have the flange type.

To replace the push-in type, you'll need to drop the oil pan to access the bearing caps, then follow the previously posted instructions in this thread. There is also instructions on the new seal packet that are vitally important, follow them to the letter. Seals are no longer available through common auto parts sources, they are now a specialty item if you get a freshly manufactured one.

[dwayneski]

i have the flange type so i am starting to remove the trans now. I have a package with the seals with 4 rubber pieces wher do they go?

[MSeriesRebuild]

i have the flange type so i am starting to remove the trans now. I have a package with the seals with 4 rubber pieces wher do they go?

Does the package have no instructions included? If your new seal is a current production seal, it should have detailed installation instructions with illustrations either inside or on the package label. You should have 4 small "Y" shaped seals, there will be a pair of 2 different types, only 1 pair will be used, the other pair does not fit your application. They seal the main bearing cap to the block. Where is your seal kit from and I might can offer more info. If it is an NOS seal package, the best advice I can give is to toss it and get a current production seal kit. This is a lot of work to install a seal that will surely leak, an NOS one will. The flange type has to be more carefully installed to get it just right; not just right, it will leak in spite of everything.

[dwayneski]

we have everthing off except the bellhouse, we cannot get it off. doese the the fly wheel have to come off first?