Rear Main Seal Replacement

[rares]

Hey guys, i am about to do a rear main seal replacement. I haven't done something like this before, and it leaks bad... i will couple it with some tranny seals as well...

my question for the experts among you is:

what am i looking at in terms of difficulty and things to watch for..?

please let me know...

i would like to get it done soon, i am loosing a lot of oil

pleeeease give me some advice, if you've done it defore

thanks

[reelizmpro]

Just did it on my S14 but I'm sure it's the same on the M20. First of all the carrier likes to get pitted and won't seal well with a gasket. Using a liquid sealant (Yamabond 4, Loctite etc) will solve this problem though. Secondly, you can install the seal at different depths so that it rides on a different part of the crank. This is important to know because the seal gouges the crank and leaves a groove which can leak oil. You don't want to install the new seal in the same location. Thirdly, make sure you install it with the supplied plastic tool so that the seal goes on evenly. This is critical since you won't be able to see if the other side is seated right or not. I used the updated Corteco seal without the spring.

[rares]

can i do this whole operation with the motor on? I am going to remove the tranny to do the seals on it, but should i take out the motor out as well or can it stay put..?

[rares]

Just did it on my S14 but I'm sure it's the same on the M20. First of all the carrier likes to get pitted and won't seal well with a gasket. Using a liquid sealant (Yamabond 4, Loctite etc) will solve this problem though. Secondly, you can install the seal at different depths so that it rides on a different part of the crank. This is important to know because the seal gouges the crank and leaves a groove which can leak oil. Thirdly, make sure you install it with the supplied plastic tool so that the seal goes on evenly. This is critical since you won't be able to see if the other side is seated right or not. I used the updated Corteco seal without the spring.

thanks a bunch btw, this is all very cool info, and good to know.. i appreciate it

[Brandon12V]

be sure the dowel pins are in good condition. they're like $2.00 and help align your trans. I reccomend replacing them every time. also, be careful when loosening the top bolts on the bell housing. external torx bolts are easy to strip and you DON'T want this. if you've never pulled a trans out of an e30 before, loosen the motor mounts so you can shift rear of trans down slightly. it will give you enough room, in the tunnel, to use a long extension. it helps to have a friend around to align the socket proper and hold it in place while torque on it. do the top ones first & be sure to support the trans case when you get down to the last 3-4 bolts. make sure to use external torx sockets, not 12pt hex. they will strip.

[Brandon12V]

also, there's a little plastic pin that is opposite(?) to the slave. it is what the end of the clutch fork uses leverage against. replace this. they wear down over time and it's worth replacing if the clutch hasn't been done in a while. usually it will come with a clutch kit.

[rares]

also, there's a little plastic pin that is opposite(?) to the slave. it is what the end of the clutch fork uses leverage against. replace this. they wear down over time and it's worth replacing if the clutch hasn't been done in a while. usually it will come with a clutch kit.

thank you sir. much appreciated. i need all the wisdom and advice i can get. i am truly excited and really want to get into this, and i knew there were kind people on here that would share some tech info...

thanks again

[Marcos]

Also

Make sure you order miscellaneous stuff like exhaust nuts and gaskets, be ready to buy a new Guibo if it's worn. Might want to rebuild the shift linkage while you're in there. Its a bitch to get at otherwise. You will have to drop both the exhaust and the driveline, make sure you mark the driveshaft's orientation for reinstall, it might vibrate otherwise. I removed the exhaust complete from the manifold flanges (with help). There are a whole bunch of things that you can do and may be necessary when you pull the trans. New trans mounts may be in order, they often crumble when you pull the thing.

I did this job for my throwout bearing and I reinstalled something incorrectly so it has to come out again, needless to say that I'm not happy about that fact. Keep everything organized and pay attention to the order and orientation of EVERYTHING..

Good Luck, you can do it!

ps a lift would help tons... oh yeah and the Bentley manual

[blocke]

If you are going to drop the tranny once, you might as well do all the "while youre in there" items. Trust me, you dont want to drop this thing again. I just did it for the third time because I f'd up my input shaft seal.
Replace all the tranny seals, clutch and TO Bearing, rear main seal, get the FW resurfaced, and install new shift linkage bushings while its all down. MUCH easier to do it all at once than drop it again and again. Good luck!

[rares]

Make sure you order miscellaneous stuff like exhaust nuts and gaskets, be ready to buy a new Guibo if it's worn. Might want to rebuild the shift linkage while you're in there. Its a bitch to get at otherwise. You will have to drop both the exhaust and the driveline, make sure you mark the driveshaft's orientation for reinstall, it might vibrate otherwise. I removed the exhaust complete from the manifold flanges (with help). There are a whole bunch of things that you can do and may be necessary when you pull the trans. New trans mounts may be in order, they often crumble when you pull the thing.

I did this job for my throwout bearing and I reinstalled something incorrectly so it has to come out again, needless to say that I'm not happy about that fact. Keep everything organized and pay attention to the order and orientation of EVERYTHING..

Good Luck, you can do it!

ps a lift would help tons... oh yeah and the Bentley manual

Thank you so much, i am truly amazed at all the little things that i didn't think about.. i am glad i asked. i just got the bentley, so now off to get all the nuts and bolts and things... thanks so much for the info

If you are going to drop the tranny once, you might as well do all the "while youre in there" items. Trust me, you dont want to drop this thing again. I just did it for the third time because I f'd up my input shaft seal.
Replace all the tranny seals, clutch and TO Bearing, rear main seal, get the FW resurfaced, and install new shift linkage bushings while its all down. MUCH easier to do it all at once than drop it again and again. Good luck!

wow, coool. thanks i will purchase all those. i do NOT want to do this again.
hehe, thanks again