Can anyone give me any advice on replacing the rear main on a LT-1? Im gettin ready to replace it this weekend. Finished the leaky intake last fall but the rear main has gotten worse. Im replacing the clutch and all. Just wandering if the seal can be replaced with out dropping the pan? (replaced that also last summer). I just need to get this thing sealed up. Tired of the clutch smoking the first trip down the track. Also tired of cleaning up oil in my garage. Any advice would be greatly appreciated. Thanks.

 

No tips? Anyone replace one of these? Does not look to complicated. I guess we just wing it from here.

 

Just a one piece seal...you'll have no problems replacing. I used pvc to tap it in evenly...i think it was about a 4" piece.

 

Good idea. After I purchased the seal it looks rather easy. Now, I just wish I had the trans and clutch out. Oh, Well.
Look out weekend!

 

I'm in the middle of doing this for the second time in about 3 days. Messed up the lips on it the first time apparently. Once you get the flywheel/flexplate off then there are 3 spots in the housing that you can stick a screwdriver to pry the old seal out (I had to use a hammer to tap the screwdriver in far enough to pry it) Clean up all the surfaces once the seal is out and make sure there is not a deep groove in the crank.

I prefer to use a little RTV around the outside just for the heck of it. LIGHTLY oil the crank and the inner lip of the seal. When you look at the seal there are two lips, one that faces towards the front of the car and one that faces toward the back. This front one is the PITA. When you put the seal up on the crank use the smallest screwdriver you have to run around the crank to help seat the forward part of the seal. Be careful not to gouge anything. You should feel the seal sort of "slip" on when you do it right. Then just use a piece of 4 inch diameter PVC to drive it home

 

I replaced it twice. I did not remove the pan. It can be pressed in with a tool. I made my own(turned on the lathe). I've used a felpro and a GM seal. I prefer the gm seal. I think it is better designed. I have a 383 w/ D1, and the increase in crankcase pressure caused a slight leak. I use Lucas oil stabilizer. It works. After you remove the seal, measure the seal gap between the crank and housing. It should be concentric. I don't remember any dowels, so, there is some slop due to the screw clearance holes. You can re-seat the housing if necessary. I think the rear seal works best when the gap is concetric.
This has been my experience.

 

To elaborate on that I also noticed one side of my seal seated SLIGHTLY better on the crank than lip on the other side, which is most likely where my leak was coming from in the first place. Didn't think to try and reseat the housing. I guess if there is a third time I will mess with it then.

 

Do u need to empty the oil from the motor first? Noob ?... but I haven't seen the seal.

 

Not unless you decide to drop the pan a little.

 

Well my car is wrecked... I WILL use my motor, either by repairing my car, or dropping my motor into another T/A boda (when I find a high-mile one). I only have 72k miles on my LT1, but if I pull the motor for any amount of time I plan to do some small stuff while it's out... fix intake gaskets, change timing chain, possibly 1.6RRs with new springs, etc. I have a rear main seal leak also, so I may tackle that at that point. I don't think I need to replace my clutch, seemed ok before the wreck, but I may like to fix that leak.

How hard is it for a first-timer to remove the clutch to get access and then reinstall the clutch (and would it be any different if I chose to go aftermarket clutch at that point?)

Thanks,

Drew

 

My engine was leaking...thought it was the rear main seal...ended up being the big freeze plug in the rear cam bore...

 

Im literally about to go attempt a rear main seal on my 97 bird myself (LT1)...

not going to lie, this will be the most extensive repair I've done yet...I've been chasing my oil leak for about 4 months now, started at thinking it was the valve cover gaskets, then the infamous LT1 intake manifold leak...did both, only to find out it was the big ol' dreaded rear main seal.


Can't afford my local mechanic to do it (wants $650 for the job in LABOR)...gotta attempt this myself...i guess just whip out the baggies eh??


I've googled and googled and googled some more...does anyone know of a step by step procedure I could read, as I really dont want to mess this up at all



Eds, good luck with your replacement too!

 

I 2nd that...

 

$650 ouch! I had my rear main done for $300, then 3 other leaks done for another $500. For the last 3 weeks i have been leak free!


Chas

 

My step by step procedures can be found here:

http://www.pharmacy.arizona.edu/staf...myz28mods.html

Hope they are helpful.