Cleaning gearbox Options

[mgardstr]

I just seperated the engine from the gearbox and wanted to clean the gearbox before replacing the seal and connecting it back to the engine. What do you suggest for cleaning off the 37 years of yuck? It's cold outside and I don't really want to be using the pressure washer, if that's a suggestion.

[pcar916]

Many threads on this subject. Search for "tectyl".

[Richard Casto]

Many threads on this subject. Search for "tectyl".

Tectyl is great for post cleaning coating. Whatever you do, especially if you are going at it with a pressure washer, only do that if you plan to pull the gear stack out, replace all of the seals, etc. The point is you don't want to force stuff into the case.

Also, in addition to removal of oil, grease, road tar and undercoating overspray, you will also find what I am seeing as two types of corrosion. The first is the pretty normal light grey you get from simple oxidation which is expected. I am also commonly finding something else that can be deeper/thick that causes pitting. It looks really different than the normal surface corrosion. I would love to talk to a chemist and/or metallurgist to understand what that is about. Anyhow, in my experience that has to be physically removed (i.e. bead blasting).

You may check with a local machine shop and tell them you have a magnesium case and see if they are setup to handle magnesium. Quiz them to ensure they know they can't use the same hot tank they would use for an iron block! Typically it would be via a water based parts washer that is like a big dish washer. If they can do it, they may be able to do it for you at a reasonable rate ($20 or so?)

Richard