Harmonic balancer seal, LT1
 

I replaced the opti in my 93 and noticed a new oil leak afterward. I retraced my steps and I was very careful to tighten the torqs for the opti. The water pump wouldn't leak oil so i"m OK there.

So I'm thinking that the harmonic balancer seal might be leaking. I always replace a rear main seal for a clutch or trans work just cause it's accessible and it's good insurance against a future leak.

I never really thought about that with the harmonic balancer. Should I expect that after removing it once the seal will have gone bad? What's it take to replace it?

You may want to clean the leak area first. I dont't know if the balancer gave you any trouble coming off, but sometimes just disturbing them can cause a leak. Even more so with synthetic oil.

It wouldn't matter if I cleaned the leak area. I can't see what's going on in there anyway, too much stuff in too little space.

It looks like I can get the balancer off without taking the water pump off. What's it take to get the seal in and out? Also, I can't remember if there was a gasket with the opti. Is there supposed to be one?

After removing the balancer you have to remove the hub (center bolt and washer). The seal can be pryed out from the front with a seal removing tool. Be careful not to scratch the cover. the seal for the opti is also on the timing cover.

Did you install a new water pump drive oil seal?

If you did, likely your oil leak comes from it.

The water pump drive seems like it's probably it, at least I'd rather replace that than the balancer seal. I took the serpentine belt and tensioner off for the opti but it looks like I might be able to get the waterpump off without disturbing those things. Please let me know if that's true and also what it takes to get the seal in and out.

Nothing I like better than re-doing the same job I hated the first time because I forgot something.

Looks like the whole mess has to come apart again for the seals. My knuckles just started bleeding when they heard about it.

As for parts, I've got the water pump gaskets, the thermostat seems to have a rubber seal. I can't figure out whether there's a paper gasket between the flange and the casting.

I'll need an opti seal, a waterpump spline seal, two o rings and I'll have to find that tool to keep the seal from bending backwards.

Can you confirm that's it?

You are not the first and you will not be the last. :thumbs:

You are saving money by DIY and having fun.

No paper gasket for the thermostat. The rubber seal is all there is.

For the waterpump oil seal installation tool a whiteboard marker makes a great install tool. There are posts all over the internet with the dimensions to cut it down.

Your list and the modified whiteboard marker should do it.

Thanks guys, has anyone used a 1/2 inch drive impact wrench with a swivel extension to get at the balancer bolts? Last time I used a bolt through one of the holes to immobilize it and a breaker bar to turn the bolts. It would be $50 well spent to get the air wrench but I don't know if there's enough room in the compartment to get at the bolts.

Hey I'm doing this exact same thing cause I had an oil leak after opti and water pump install! Glad to see I not the only one, and won't be the last either I bet. Lol fun fun fun. But I am at tje point where I have had so many c4s I can't get it all apart in less than an hour and will put it all back together I'm tje morning and that's just saying that I was dumb enough to have to do this more than once! :(

When I did mine, I had a little wear ring on the hub shaft where it rubs on the seal. On advice from another builder I got a "hub seal saver". It's a little slip-on sleeve that goes over the seal area. It looks like the lower end of a redBull can that has had the top cut off. It's very thin but makes the hub shaft smooth and even again. You heat it up in the oven and slip it over a cold hub shaft. A lot cheaper than getting a new hub.