OK I struggled mightily getting the lower unit off my 1993 250TXRR it finally dropped. Trying to reinstall it back up but it is not happening. I suspect the splines are not in the best of shape. Ideally I want to try hitting them with penetrating oil and wire brush. I'm fabricating a long tool w/ wire brush (25" shaft) and contemplating what I can use to shoot oil up at it. Hoping this will help clean the splines that I'm sure are full of crude/rust? Any ideas would be helpful. My mechanic is telling me it looks like a lost cause ! Is this really true ?