[mcgarrett]

I use mineral spirits/paint thinner in my parts washer and that seems to do a great job of final cleanup to remove any old gear lube, dust, and gook. Use your air gun to blow everything dry and you're ready to go.

If your transmission has bronze synchronizers, be sure to use a good quality GL-4 (API rating) gear lube. GL-5 gear lube contains chemistry that will damage bronze parts over time.