jacob80 Posted April 14, 2010 Share Posted April 14, 2010 (edited) Hey fellas, I did a little digging and couldn't find anything for my specific question. While I have the transmission out, I want to replace the rear main seal. I've discovered traces of oil on the back-side of the motor, just below the crank/rear main seal. The motor is still in the car, of course. What is the best method to do this? Is it a matter of prying it out and tapping in a new one with a wooden dowel? What is the risk/potential damage if done incorrectly? What is the appropriate installation? Thanks guys! Engine: 1983 L28ET Edited April 14, 2010 by jacob80 Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted April 14, 2010 Share Posted April 14, 2010 Piece of cake. Definitely do it while you're in there if it's leaking. Now - you say "traces of oil on the backside of the motor" - can you physically see it dripping down from the rear main? You could have a bad input shaft seal on the tranny causing "what looks like" a motor oil leak. Inspect both, and heck - for cheap insurance - replace both. Get a seal puller from AutoZone etc. and just wedge the hook part under the lip of the seal and pull it out. Clean the seal area well with brake parts cleaner. On going back with the seal, I slather the inner lip of the seal with white lithium grease, and then put a little of it on the outside of the seal so it goes in a little easier. Biggest thing you DON'T want to do is have the seal go in cockeyed. Hang the seal by the lip around the back of the crank and push in evenly as far as you can by hand. I use the backside of a large® socket and gently tap the socket with a hammer, moving the socket all the way around the circumference (evenly) of the seal until the seal is flush with the back of the block. Feel around the seal with your fingers for any high spots and correct with hammer/socket. Done deal. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted April 14, 2010 Author Share Posted April 14, 2010 Wow...seems simple enough! I believe I was getting the typical oil leak coming from the hole between the transmission and the block, which isn't for certain the rear seal, but it was pretty oily on the back side of the motor. The motor and transmission were rebuilt, but I just have a bad feeling about the seal that is in there now because we had a hell of a time getting it in there along with the side seal and rear main cap. If it is really this easy, there is no question I will do it ASAP! Do I absolutely need the puller, or can I figure something out myself? I just don't do enough of these to justify it, perhaps they do rentals at autozone? I have a puller for crank pulleys and such, so maybe that could work. Thanks for your help! Quote Link to comment Share on other sites More sharing options...
pcakes55 Posted April 14, 2010 Share Posted April 14, 2010 The autozone near me lends out tools. I think you have to give them a deposit which you get back when you return the tool; I'm sure it the same near you. Quote Link to comment Share on other sites More sharing options...
jasper Posted April 15, 2010 Share Posted April 15, 2010 (edited) I do this ALL THE TIME. Take a small pick (small automotive tool). Make a small hole in the face of the seal(hammer), closest to the outer edge, but inside the metal lip. Stay away from the crank. Screw a long thin sheet metal screw into the hole 1- 1 1/2 turns. Stay away from the crank. Use a pair of diagonal cutters to grab the screw and lever it out, works every time. Place new seal into position, use old seal UPSIDE DOWN on top of the new seal. Tap lightly with a hammer all around. Remove old seal. Done. Edited April 15, 2010 by jasper Quote Link to comment Share on other sites More sharing options...
jacob80 Posted April 15, 2010 Author Share Posted April 15, 2010 Awesome! Sounds easy enough I suppose. Hopefully I can get it out that way if possible, thanks! I've noticed that the seal in there right now is not completely flush with the back surface of the block. I remember when we rebuilt the motor that it looked a little off, but now I'm seeing it really is, like one side was pushed in a little more than the other. I want the new seal to be flush with the back of the block, correct? Quote Link to comment Share on other sites More sharing options...
woldson Posted April 15, 2010 Share Posted April 15, 2010 Make sure you lube everything up upon re assembly. Anything dry, dragging can cause microscopic tears which can lead to premature failure. May take along time, but it will. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted April 15, 2010 Author Share Posted April 15, 2010 That makes sense. Which of these two do I need to pull it out? Autozone Pullers Link Quote Link to comment Share on other sites More sharing options...
jacob80 Posted April 15, 2010 Author Share Posted April 15, 2010 Ok, I just visited Advance Auto and picked up one of these: Hopefully this is what you guys are talking about when you say seal puller. Wish me luck! Quote Link to comment Share on other sites More sharing options...
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