Question about changing rear main seal

[fstik]

HI,

The rear main seal is leaking on my Bronco. I had a buddy who told me that he was able to change his without removing the engine or drivetrain, anyone have any details that would support this? I have another 302 on the engine stand but it isn't ready to go in, so I want to try and fix this without pulling the motor unnecessarily. Thanks in advance.

fstik

 

[la77]

I changed mine with the engine in the bronco. I got alot of oil in my hair.
you have to drop the pan and remove the rear main cap. drive out the old top half and install the new one. you will have the bottom half out to change easily. on an unlifted bronco you have to jack up the front bumper a little to be able to get the pan out. the engine I did this in was severely worn out and mosquito patrol when running (smoked). slowed the leak down some but still leaked. I think the crank was badly worn and that was why it still leaked. every 302 I have owned had a leaking rear main seal. even my freshly rebuilt 5.0 h.o. Ford only has one size rear main seal for 302. Gm has "heavy duty" rear main seal available for worn crank, whish for did too.

sorry for the ranting. it isn't that hard. it took me a couple of hours to do.
but if you are going to put in another engine in next 3 or 4 months I would just wait

 

[thegreatjustino]

I was changing my clutch at the time that I replaced my rear main seal, so I had the transmission out like a lot of people had recommended when replacing the seal. Once I got the oil pan and bearing cap off, I had no idea why people say to take the tranny out to replace the seal. I would have had plenty of room to get it done. As long as you can get your oil pan to clear the front diff to remove it, it is a piece of cake to change.

 

[Doyle]

If you get the new style rubber seal instead of the rope you will need to drive the small pin out of the cap so that it doesn't deform the new seal. Stagger the seal ends a little so they don't line up with the cap ends. If you have help, have them rotate the crank with a socket and breaker bar while you feed in the upper half. It'll go in easier this way. Don't forget set brake, chock wheels, and take it out of gear if you use this method.

 

[pate79]

I have done it both ways it was the first thing I did to my bronco so I took out the transfer case and transmission. It made it easer to clean them and it takes two days. The second time was on a buddy’s and we just dropped the oil pan and loosened the crank bolts (just enough to barely move the crank shaft). We then used some plastic to push out the top seal (making sure not to score the block of course). Oiled up the new ones and pushed them in (making sure the seal lip was facing the right way). You also need to offset them about an inch from the bearing sealing plane as stated in post above. That way only took half a day. There was no benefit gained by removing the transmission except staying cleaner that’s all. Make sure to get the new rubber seals and not the rope one.

Happy wrenching and remember safety, safety, safety!

 

[fstik]

Excellent! Good to know that I can do this in the Bronco since I was too Lazy and did not replace the seal WHEN I HAD THE ENGINE OUT!!! Thanks for everyone who responded.

Robert