VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Media blasting 1928 3-speed internals

Recently tore my three speed transmission down for my truck. The inside of the case did have what resembled oil in it, but probably had moisture in it or something as things are covered in surface rust. The gears look pretty good and the shafts are clean where the gear clusters were.
I was thinking of media blasting with either glass beads, or walnut shell media. I have read on the topic and from what I can see it has been done by guys. Others say no, but it is usually referencing a more modern trans that has sycros in it.
Thoughts?
Thanks,
David

If everything is clean inside with just some surface rust, I would make sure all my bearings and seals and machined surfaces are good. Maybe steel brush some spots if you like. Then if you still have doubts, fill it with new oil and turn it. If it's smooth then move on and you're good. If not then troubleshoot from there. I promise you though, that surface rust will not be the problem.

David,
Blasting with nut hulls cannot hurt anything.

Mike

I agree with Mike

Soda blasting with baking soda should also work.
My nephew has used soda blasting on alloy carburetor bodies and it worked great.

Great. I actually picked up some all natural walnut shell cat litter at the box store (it has nothing added to it) I feared it a little coarse to go through my blaster and I was right. I dumped it in my vibratory tumbler and put a couple of the gears in. Will see what I get.

Blasting with baking soda does work and leaves a smoother finish than a lot of other materials though I have not tried walnut shell.
Tony

At some point I would like to try blasting something with soda just to see how it works.
With this project I started by putting the cat litter walnut shells in my tumbler with a couple of the smaller gears. That broke down the cat litter enough to be used in my blaster then. It was too coarse otherwise. I then blasted the bigger cluster and shafts. It got things clean without too much stripping. It appears the gears new maybe had a pickle and oil finish to them like new steel has. It didn't strip that off, but any of the wear surfaces are nice and shiny now.
It did nothing for the case. After degreasing and scraping I put my regular sand back in and blasted the case and then washed in in super hot water and dawn dish soap. Of course it flash rusted so I used my variety of wire brushes on my air tool to clean up. Resulted in a nice clean case ready for paint.
Now I just need to get some bearings and bushings and put it back together, and figure out how I am going to clean up the shifter and cover plate.
Thanks for the input.
David