Welcome to the Corvette Forums at the Corvette Action Center!

Seal replacement


Well-known member
Feb 9, 2001
Shreveport, LA
1981 silver/blue: two tone
I want to replace front and rear seals and gaskets. Any advice, especially on front and rear seals. I am looking for the most painless way.
Are you really sure you want to attempt this? How much experience do you have working on engines? Do you have a torque wrench and a harmonic balancer puller? If you are sure you want to do this yourself I can walk you thru it.
Well....I really didn't think it was going to be that big a deal. I have a torque wrench, but no harmonic balancer. It doesn't appear that the rear seal is a problem, what is the problem?

One of the best tools I have that gets the least amount of use next to my ring compressor tools is an awesome front balancer puller/installer from Summit Racing (800)-230-3030. I don't recall how much I spent on it, but it allows you to remove and install the front pulley (gaining access to that nasty front seal) with a limited amount of space and without a hammer. It comes with instructions. I would suggest to anybody considering this job to buy one and hang on to it.

On the older blocks, the rear main seal can be changed without pulling the trans. You will have to jack the car up, drain the oil, and drop the oil pan. You will have to pull the last main cap and oil pump off. The lower portion of the seal is right there in the cap, and you will have to get a clothes hanger or other small thin tool to push the upper part out of the block.

Read the instructions, repeat the procedure and you are on your way to a dry tight set of seals and clean garage floor.

Oh, you need the torque wrench to reset the torque on the main cap that you pulled to change the rear seal.
Thanks 69' thats kind of what I was hoping for. Some encouragement and guidence. We'll let you know how it turns out. I really can't find where the car is leaking, but it is running down the right frame and dripping off. I had planned on changing the oil pan gasket, and rear seal, but as long as it was up, I figured I would change the front seal. Some earlier comments indicated that their front seal was leaking.
Thanks again

Maybe this will save you some hassles but I keep seeing in either Jegs, Summit, or Eastwood catalogs where you can get a dye to put in your oil and use a black light to detect the source of the leak. Might save you from an expensive and unnecessary repair bill down the road. Like 69 said too, the rear main isn't all that bad of a job, just time consuming.

You might want to check your valve cover gaskets, I've been fooled by them in the past, thought I had major oil leak and it turned out the valve covers came loose.
Thanks Scott,
What are you doing on line at 1:00am, sleepless in Tampa?? I have looked really close at the valve covers and they don't seem to be leaking. Like I said, alot of it is on the right frame, and I can't see where it is coming from. I really believe it is coming from the oil pan, but I want to change everything. I do have a visible leak in front and back of the intake manifold, so I will change that, the oil pan, real seal and maybe the front. The jury is still out on that. Actually, I decided to get the car painted since I decided to change the gasket. I really am confused.
Oh yea Scott, one more thing. I really do not know what you were really referring to, but as a Geologist, Oil floresces under a black light. So I am not sure what the difference would be.

1:00am I'm hard at work....posting on the forum and talking to Brutus the trouble maker.

I remember seeing this dye you could put in your oil that helped you find leaks, I thought you used a black light but you would definately know better than me...now I'm going to have to check some of the old Eastwood catalogs and find this stuff for you. I know that the loccal shop used it on an old girlfriends car because there was just too much oil on her motor....why I dated a girl with car maintenance habits like that I'll never know, or at least tell everyone here on the forum :D

Sounds like you are a bit confused so just do everything! I'll post the dye stuff in the morning when I get home. Good luck on the repairs.

OK, I found it in the Eastwood catalog. It says; Dye system helps you locate the source of those hard to find leaks, blah, blah, blah....Use the UV lamp to pinpoint the source of the leak. Dyes do not alter the performance of fluids. System includes UV lamp and dyes for engine oil, trans, and coolant. YIKES: cost $89.99 Must be for the light because it shows below the seperate fluids as being only $4.50
Thanks for the info Scott. It must be true. I think I will pass on the $90. Say hi to Brutus, I have seen him a little active as of late. Hope to see ya both in BG this fall. Also hope work and school is doing well for you.

No problem, I'll tell the big freak HI :D Unfortunately won't be in BG for the SharkFest, I'll be out of school by then but if I still have a job I'm scheduled to start work the Tuesday before that weekend and there's no way to switch my schedule around. Take plenty of pics for me! And make sure you throw plenty of peanuts at Dale and his Mrs. for me :D Hope all is well with you and your son.
fix'n your oli leak

just a thought on your oil leak.when i bought my 81 i was told the rear main needed replaced.it looked like it too,oil was all over the back of the engine.my buddy told me to replace the valve cover gaskets first.i took my time and degreased the engine and replaced the v.c. gaskets.that was the problem.i also replaced the front seal and balancer.just don't hammer the balancer on like some do.they make a nice installer to that job.
good luck!


Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors


MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Advertise with the Corvette Action Center!

Double Your Chances!

Our Partners

Top Bottom