Re: OMC Lower Unit Sealant and Questions

I have no experience with the sealant materials you mention, but I can offer some info on the leaking seals.

First you need to nail-down (if possible) if the new seal is leaking around the OD (where the seal meets the case) or the ID (where the shaft penetrates the seal). If the former, you need to look at things like seal-to-case fit, and so on – sometimes driving the seal into the case will shave off critical outer material, causing leaks at that joint. If the latter, the most common way seals are damaged is by burrs or sharp splines on the shaft that is being sealed, as the shaft passes through the seal lips, damaging them.

Did you pilot the seal onto the shaft (even with a turn of tape, if you didn’t have a seal pilot tool)? It’s so very easy to put multiple little cuts into those seal lips if you don’t protect the ID of the seal from the OD of the shaft. Your eye will miss them, but unfortunately the oil will not.