Alright yall. Just picked up a 92 Blazer. 4WD 5.7L Auto trans. Glad to have it! has an oil leak. Still seeking the exact location of the source but leaning towards the rear main seal. No i have not yet read my manual. Left it at home and cant kill the curiousity while at work. So...obviously first need to verify that it is the rear main if im goin to replace it. The big question i have though is does the crank have to come out if it needs replaced? Ive seen a couple people talking about how its as easy as trans out, pop that cap, replace the seal and pop it on. Others seem to have to drop the crank. Any help is appreciated but go easy not looking for anyone to research for me just off hand knowledge. soon as the book is in my hand ill be reading it as well.

 

ive never seen a engine where you have to drop the crank to replace the seal. most like you said you take the tranmission out and the flexplate or flywheel out of the way and its right there staring you in the face.

easiest ones i ever seen are the 4.0L in jeeps, they are two pieces you just drop the oil pan and you just kinda tap them in with a hammer.

also make sure its not the back of your intake or your distributor leaking down onto the trans making it look like its the rear main

 

A '92 is going to have a 1 piece rear main seal which I believe started in the late 80's. I think it can even be done with the oil pan still on. I'm not 100% sure on that though. I do know that the crank does not need removed to change the seal.

 

It was to my understanding that on the back of the block there once the trans is out of the way, that is only the rear main housing though correct, which also contains a seal. the rear main seal itself is actually held in by the rearmost main bearing was the impression i given. i appologize though ive yet to take a peek at the manual of course.

 

ok gents. finally i looked at what i should have in the first place, the maint manual. for the 88 and newer v6 and v8 small blocks. the rear main seal is located in the rear main housing which is in fact removable without needing to drop the crank. easy as apple pie if youve pulled a trans or two or three. thanks for the input yall and hopefully i can rule that problem out in general and not worry about pullin the trans anyhow.