Muncie cleaning

[BillOhio]

Started cleaning gunk off my transmission today. Main case is pretty nice but the tail shaft has a different look to it. I was just going to clean it but I do have some walnut hulls I could run thru the blaster. What have you seen done that works and maybe what I have is normal? Front was covered in oil

[ko-lek-tor]

Bill, I had a gnarly looking smog pump that was stained and had that white chalky corroded appearance. I used a solution that is made to clean a/c A coils. It is an alkali, I believe. Will have to look at it tomorrow and see what the ingredient is. It foams up and has to be rinsed thoroughly, but it did the pump justice IMO. I don't have any before pics. I get a chance, I will take a pic. Just an idea.

[68camaroz28]

I had some alum. trailer cleaner I used on some parts and it worked pretty good to remove some stains but after the bath I glass beaded between 15-20 PSI. Was slow going due to the low pressure but the alum skin was not altered and it gave the part a really fresh new look.. Got the idea for the low PSI from one of JohnZ's comments. Again, slow going but it worked well and only took time and not $$ as I already had the alum. trailer cleaner (mixed so many parts of cleaner to so many parts of water). Use distilled water!

[BillOhio]

I think the oil that was all over the main case kept it nice. Wasn't any on the back. The back is also alot rougher casting. I have seen the trailer wash. I might have some aluminum prep stuff for painting too.. 

[z28z11]

I'd stick with chemical cleaning. Carb cleaner and brake cleaner both work acceptably: I used a combination of brake cleaner (dip bucket) and Comet Cleanser on my valve covers/intake during a rebuild in '75 - came out pretty close to the original appearance IMO. Glass beading always leaves a tell tale look to it -

Steve

[firstgenaddict]

The tail shaft housing should have the same finish as the Z28 valve covers or the steering box cover (die cast aluminum) the main case should look like a Z28 aluminum intake (it was pour cast in a green sand mold then into a vibratory tumbler with steel shot to remove the casting sand).



These are cast aluminum seat stands which are fresh out of the vibratory tumbler loaded with steel shot.

[BillOhio]

Thanks James. Should the main case be a little brighter then?

[firstgenaddict]

Yes, anything die cast will oxidize quickly, the skin created through the vibratory tumbler with steel shot appears to slow the oxidation process and slightly polish the casting.

 
The appearance of your main case is pretty nice, if you degrease it then use carb clener and a tooth brush it will look great, the tail shaft may require something more powerful (foaming oven cleaner?)  as it appears to be heavily oxidized.
If you use oven cleaner tape off the rest of the trans as it is very powerful and you don't want to mess up your cast finish.
Oven cleaner will also take the polished look off a set of aluminum valve covers.

[BillOhio]

Thanks James. The main case was covered in oil film. Was disgusting but probably helped keep it nice

[ko-lek-tor]

Went out to the shop just for you Bill. I am sick today and all weekend. Anyway, that cleaner I used is called Nu-Brite. Here is a link:  http://www.nucalgon.com/products/coil-cleaners/condensers/nu-brite  Bottle says,"contains Sodium Hydroxide".

[BillOhio]

You guys are great help! Now if I didn't have to get tractors ready to plant I could get something done!
Get to feeling better too. If you like basketball was a good weekend to be shut in. Some great games so far