Transmission cleaning...

[motogman]

I am doing my research (using the search functions) but wanted to also solicit advice directly as I search previous posts.

What have others done to clean the transmission (915) case before a tear down?

What is a good cleaner for brightening the surface after a good power wash and scrub with simple green?

Any concerns with surface oxidation etc. after cleaning?

Thanks in advance for sharing your experience...

[E Sully]

I;ve been considering trying this.
Extreme Simple Green® Aircraft & Precision Cleaner

[304065]

search here for Grady Clay and Tectyl.
Bottom line is that the trans case, after being thoroughly cleaned, should be coated with a petroleum product to keep it from oxidizing.

[Tippy]

I bought STP Ooomph:

STP® Multi-Purpose Cleaner | Oomph!® Cleaner and Car Degreaser

Whipped decades of grease's arse! Very impressed.

Has a mild acid IIRC, so the case looks brighter too.

[Spenny_b]

Have a search through my build thread (below), towards the last 4-5 pages iirc I went and cleaned my transmission again after it stood for a few years. Use AluBright - not sure if its available over there...then used Dinitrol clear wax to protect it (I painted it on by hand rather than using the Schutz gun to apply it)

[KTL]

The aluminum cases do OK w/out any protectant if its a car that just sees occasional use in nice weather. If its a car that gets driven rain or shine or snow, i'd put a protectant on it. Especially if you're in a region with salty roads.

I would clean the case with a good degreaser like Simple Green or Oil Eater and use pressure washer. To really brighten it up, I recommend you soda blast the case sections. Even with the pressure washer, there's going to be some areas that you can't get clean and you need some abrasive help that the soda blasting will take care of. The diff housing side cover is typically the crappiest looking part of the trans, due to the deep nooks in the cover along the reinforcing ribs.

[Jcslocum]

I tried the simple green and pressure washer route on my 901 trans and was really disappointed. I then grabbed the Sonax wheel cleaner, let it soak and then blasted again with the pressure washer. The pictures tell the story.

[johnman001]

for my $0.02, I use WD40, a brass bristle brush, and lots of paper towels. The WD40 dissolves lots of goo and the brass brush doesn't scratch up the outside of the trans. Your mileage may vary.

If it's apart, I put the whole case in my parts washer. My solvent is safe for aluminum or magnesium.

Dawn will also work, but takes more scrubbing.

Once clean and dry, I usually spray them off with something like Gibbs brand oil to keep them from oxidizing too quickly and it keeps stuff from sticking to them.

[motogman]

Great responses - thanks for sharing your experience & ideas - keep them coming.

I read about Gibbs oil (I think) used on cleaned up fans as well. What is Gibbs oils and where do you get it. What makes it different from 20 et or extra virgin?

I am always learning on this site!

[motogman]

That was supposed to be 20 weight (as in oil...)

[Dave Kost]

I did the WD-40 and brushes, it works but alot of work. I tried the Citrol, took the tranny to a quarter car wash. Three soakings with the Citrol and high pressure spray and all done.

I got the Citrol from a local Napa store.

[Spenny_b]

Good shout for WD-40 - I didn't think to try it for the transmission case but am always surprised how good it is with cleaning other parts of the car

[michael lang]

I went with plain old mineral spirits and a brass brush. Spent a couple of hours with it. This is what I started with:

And this is what I ended up with:


Time well spent in my opinion. Good luck whichever way you decide to go.

[jrhb]

About pressure washing, can you just start spraying the transmission or do certain areas need to be covered or blocked off?

[Determined]

I have done several with Oven cleaner, I let me transmission sit in the sun for a while to warm it up and sprayed lots of oven cleaner then with a wire brush scrubbed heavy build up areas then pressure washed it off. Overall, the first wash removed almost all of the build up. The second wash and scrub cleaned it all up nicely.

Oh, I did use foil tape to cover the top vent opening, this is the only area I covered up.

[db9146]

If you are cleaning a trans with a magnesium case, you will want to protect the raw magnesium from oxidation (ever seen raw aluminum left outside? magnesium is worse).

There are some references to a product call Tectyl but I uncovered a newer, seemingly safer solution for protecting the raw magnesium called Prekote by Pantheon (PreKote Surface Pretreatment - Pantheon Enterprises). It is used to seal the raw mag before painting and seems like a simple process. I found it in a spray bottle here (Pantheon PreKote 065-1002 Surface Pretreatment - Quart at SkyGeek.com).

[toddu]

Originally Posted by jrhb

About pressure washing, can you just start spraying the transmission or do certain areas need to be covered or blocked off?

You need to be careful where you spray. You also MUST block the vent port on the top side.

Todd

[Mark Henry]

Originally Posted by toddu

You need to be careful where you spray. You also MUST block the vent port on the top side.

Todd

I agree.
Personally I wouldn't pressure wash a case unless it's coming apart the next day. You can blast right past the seals.
I also wrap the stubs, input shaft and shift rod tight with old rags.