[The original thread containing these posts already had over 40 illustrations and remains available as Rebuilding Gear Case of 48SPL-Part 1. Threads with so many images are difficult to load for readers with slow and intermittent internet connections, which apparently included the author's internet connection, I have split the thread into two parts to reduce the loading time and minimize the problem with images failing to load for some readers.--jimh]
I am re-building my 1996 Evinrude 48SPL gearcase. The propeller shaft bearing carrier has seals at the outer end.
A double-lipped seal
A single-lip seal
I found that use of two single-lipped seals (that used to be installed back to back) has been superseded by one double-lipped seal.
I was able to install the new type seal deeper into the seal cavity. That gave the the seal surfaces fresh metal to ride on. There is room to add another of the original single-lipped seals on top of the new double-lipped seals. At surfaces of a new seal would ride at the outermost part of the seal cavity and still be on the correct part of the propeller shaft.
Is an extra seal beneficial or detrimental to the other seals?