How do you clean your transmission?
- Thread starter DanielForest
- Start date
Dr.Jeff
True Classic
If you look online they still are. Along with a host of other household consumables.
Steve Hoelscher
True Classic
Cleaning transmission cases is one of the worst jobs. The porous surface retains everything, the years of gear oil and road dirt caked on, and then the 40 year old, dried out, Cosmoline.
The porous surface is hard enough without all of the other crap but then add all of that and its a nightmare. I have tried all of the popular degreasers and while they will remove most of the surface oil, it simply won't penetrate the years of caked on gear oil, clutch material and road dirt. Petroleum based cleaners work better in most cases. Mineral spirits or kerosene but they are not fun to deal with.
My go to is a 50/50 mixture of Purple Power degreaser and water sprayed on the case to soak as step one. Step two is a pressure washer, the best alternative to a commercial hot cycle cabinet type parts washer. The pressure washer is about the only thing that will really get the crud out of the pores. Typically, step 3 and 4 is a repeat of steps 1 and 2. Sadly, this typically doesn't have much effect on the hardened cosmoline. I use a spray bottle filled with mineral spirits to soak the cosmoline regularly over several hours. I do this with the case sitting in a heavy duty plastic tote to keep from making a mess. The mineral spirits softens the cosmoline and the pressure washer can then blast it away.
What's left is the bare case, which often shows a considerable amount of corrosion/oxidation that can't be removed with solvents. A wire bush works but that's slow and tedious. If the corrosion is problematic, I media blast the cases. That makes them very nice but you don't ever want to use an abrasive like sand or glass beads. Walnut shells actually work nicely and the case can easily be washed clean and blown out with compressed air. Getting sand or glass beads out of a transmission case is nearly impossible without a commercial cabinet washer.
I don't recommend using a pressure washer on an assembled transmission. Its far to easy to blow water right through the seals and into the case. I suppose you could soda blast an assembled transmission and soda blasting does a pretty good job. But then you need the equipment or to take it to a commercial blaster.
This is a case that was pressure washed as described. It is being prepped for painting here:
It takes me about 4 to 5 hours to clean and prepare a case for assembly.
I should note that pressure washing is often necessary to get the inside of the case clean enough to be serviceable. This is because the fine metal particles that contaminate the gear oil, in a lot of severely worn transmissions, sticks into the pores of the case and simply can't be washed out with conventional cleaners. And like in an engine, the hot oil will loosen it up and circulate it through the system and contaminate the new gear oil and wreak havoc on your new rebuild.
This is an example of such a situation. The entire interior of the case is coated with varnish, fine metal particles and dirt. A solvent and scrub brush will not clean this adequately.
Even at that the case can be permanently stained, as you can see in this picture. There is a clear line where the old, contaminated, gear oil sat and left clear indication of what the gear oil level was inside the case. Despite the stain you can see what a thoroughly cleaned case looks like.
The porous surface is hard enough without all of the other crap but then add all of that and its a nightmare. I have tried all of the popular degreasers and while they will remove most of the surface oil, it simply won't penetrate the years of caked on gear oil, clutch material and road dirt. Petroleum based cleaners work better in most cases. Mineral spirits or kerosene but they are not fun to deal with.
My go to is a 50/50 mixture of Purple Power degreaser and water sprayed on the case to soak as step one. Step two is a pressure washer, the best alternative to a commercial hot cycle cabinet type parts washer. The pressure washer is about the only thing that will really get the crud out of the pores. Typically, step 3 and 4 is a repeat of steps 1 and 2. Sadly, this typically doesn't have much effect on the hardened cosmoline. I use a spray bottle filled with mineral spirits to soak the cosmoline regularly over several hours. I do this with the case sitting in a heavy duty plastic tote to keep from making a mess. The mineral spirits softens the cosmoline and the pressure washer can then blast it away.
What's left is the bare case, which often shows a considerable amount of corrosion/oxidation that can't be removed with solvents. A wire bush works but that's slow and tedious. If the corrosion is problematic, I media blast the cases. That makes them very nice but you don't ever want to use an abrasive like sand or glass beads. Walnut shells actually work nicely and the case can easily be washed clean and blown out with compressed air. Getting sand or glass beads out of a transmission case is nearly impossible without a commercial cabinet washer.
I don't recommend using a pressure washer on an assembled transmission. Its far to easy to blow water right through the seals and into the case. I suppose you could soda blast an assembled transmission and soda blasting does a pretty good job. But then you need the equipment or to take it to a commercial blaster.
This is a case that was pressure washed as described. It is being prepped for painting here:
It takes me about 4 to 5 hours to clean and prepare a case for assembly.
I should note that pressure washing is often necessary to get the inside of the case clean enough to be serviceable. This is because the fine metal particles that contaminate the gear oil, in a lot of severely worn transmissions, sticks into the pores of the case and simply can't be washed out with conventional cleaners. And like in an engine, the hot oil will loosen it up and circulate it through the system and contaminate the new gear oil and wreak havoc on your new rebuild.
This is an example of such a situation. The entire interior of the case is coated with varnish, fine metal particles and dirt. A solvent and scrub brush will not clean this adequately.
Even at that the case can be permanently stained, as you can see in this picture. There is a clear line where the old, contaminated, gear oil sat and left clear indication of what the gear oil level was inside the case. Despite the stain you can see what a thoroughly cleaned case looks like.
johnph
True Classic
But, if we paint it, we loose the original two original factory orange stripes. These stripes can mean something. Maybe, in 30 years, those stripes will add fifty dollars to the value of my 76 X. Does anyone know what the 2 orange stripes indicate?
Dr.Jeff
True Classic
Vapor blasting is kind of interesting. For some reason it was very popular in Europe long before it caught on here. Basically is it media blasting where water is mixed with the media (often glass beads) to reduce dust and keep the surface cool. Those huge portable systems you see advertised from "Dustless Blasting" are the same thing, but they prefer to not call theirs "vapor" for some reason. It does work great on alloys but has an inherent problem when used on ferrous metals. Namely rust. They have a 'additive' they can add to the water to act as a rust preventative but it doesn't seem to work very well. Most often rust still develops almost instantly. Which makes sense; you expose raw fresh iron to water in the process. Like most things it has its place but isn't a universal answer. It would be good for the trans case if a non abrasive media is used, to avoid leaving traces behind on the inside surfaces.
Yves
True Classic
What I did ...
- Clean with high pressure washer.
- Dismantle the transmission.
- Sand blast the case.
- Apply "Walter Zinc-100 paint"
- Apply 2K Clear coat.
- Reassemble everything.
Done !
Look simple but takes many hours ... But great result, resist to the dirt and easy to clean. the 2k clear coat seal the metal porous.
https://i.imgur.com/riL2SGb.jpg
- Clean with high pressure washer.
- Dismantle the transmission.
- Sand blast the case.
- Apply "Walter Zinc-100 paint"
- Apply 2K Clear coat.
- Reassemble everything.
Done !
Look simple but takes many hours ... But great result, resist to the dirt and easy to clean. the 2k clear coat seal the metal porous.
https://i.imgur.com/riL2SGb.jpg
Dr.Jeff
True Classic
The zinc paints make a cool looking finish. But they tend not to be very durable on their own, so your clear coat over it was a good idea.