I replaced the crankshaft seal (rear seal; seal between the engine and tranny) on my 94 Accord with a Fel-Pro one from Amazon last summer because the original was leaking. The new one is also leaking, and I am using high-mileage synthetic. I switched to conventional, and it is still leaking. I have added AT-205 for about 3 months. I think the leaking is less because the spots on the cardboard are smaller.

My question is, how long will it take for the leak to stop completely if it does at all? Am I looking at months?

I cannot imagine what went wrong with the installation, and the Amazon reviews for the seal look pretty good. I took my time and was as careful as I could be. I followed Honda's instructions, leaving a gap within a certain spec. I think next time I will used a hydraulic press to set the seal in just to make sure it is absolutely even all around.

Do you have any similar experiences?

 

It is possible that you got a fake fel-pro seal from an amazon vendor. The seals are pretty simple, either the seal somehow got damaged or the spring didn't seat, or the crank shaft or the housing has a scratch letting the oil pass by.

The most likely permanent fix is to go back in a replace the seal. Not sure how well stop leak will work, but definitely top off the oil until resolved. Using the crank bolt or same size bolt and a socket to drive in the seal would work. I don't think you'd need something hydraulic to press it in.

I also remember reading/seeing something where the crank can get worn down where the original seal sat for many years. So when you install the new one, you want to get it past that groove? Something to inspect while you are in there. Clean the crank and housing with something like fine steel wool or a red scotchbrite to remove any buildup on there that can possibly cause a leak. Also take a look at the seals for the balance shafts, etc while you have the timing cover off.