Transmission Flush

Hey gang,

I keep having to change the fluids in the tranny/transfer case because of water. It's kept indoors, and not driven in inclement weather (no roof/windshield). Any ideas on what to use to flush the two? I was thinking kerosene, but I don't want to do anything to hurt the gearboxes. Suggestions?

 

I usually open up the drain plug on the tranny and spray a good amount of brake clean in there until most of the old sludge is cleaned out, then refill with gear oil.

For the transfer case, I take off the bottom cover and the PTO cover and spray the brake clean all in there, making sure all the gears are clean and that there's no sludge left on the inside of the case, then just refill it with gear oil.

- evan

 

Interesting Brian, never considered flushing that way. Maybe jacking up the rear axle (tires off the ground, in 2WD) and letting it run for a few minutes would be a more gentle way to clean it out with the kerosene?

 

All answers stated by other members were good. I might suggest removing the shift tower on the top of the tranny so you can get better access to the inside of the tranny and really spray it out well. It's hard to really clean it out well by spraying through such a small hole like a fill plug. I had a similar problem on a 72 cj and used a spray lubricant like wd-40. The brake cleaner is a good idea though since it is more water soluble than an oil-based product. It should actually mix with the water and act as carrier to get it out. Also as the brake cleaner evaporates it should take the water with it.

 

Ooops, yeah I forgot to mention that I take the shift tower off when I spray it out with brake clean... That would be pretty difficult to get to everything through that little fill hole!

- Evan

 

Hmmm, I've heard of people dumping in alcohol in fuel tanks to get water out (filled them with water so they could weld on them). Would that work? Dump in a bunch of rubbing alcohol and when you dump it the water should come on out because water and alcohol can mix. Alcohol evaporates pretty fast so a little time sitting with everything opened should let it clear itself out.

I don't know, I'm just thinking out loud. All these sound like good ideas.

 

Personally, I'm wondering why there is such a condensation problem.

 

most likely because I didn't drain it very well the first two times I ran it. I took the suggestion of jacking the rear wheels up and putting it in gear to get it warm. Drained the case, and thinking ahead for once, pre-heated the gear oil beside the barrel stove before I pumped it in. Got it all done, started it up, and the water pump is leaking like a screen door on a submarine... oh well, just another trip to my FLAPS... they know me by name now...

 

Just FYI rubbing Alcohol is around 30% water, if you want to absorb the moisture I would suggest getting a pure alcohol.

 

Where is the water coming from that is getting into your Tranny/TC?

My JEEP sits outside, and I don't have that problem when it rains.

 

you can use atf to flush the trans. we drained out old, filled to spec; did that with my friends sm420 that had an enormous amount of water in it. drove it for a while, then refilled with sta-lube trans oil. shifted much better after the water was out.

 

Holy old thread revival! The previous post to Chris_bar was 2007!

 

I never noticed. Wondered why there were so many posts to it.


I have been guilty of the same thing, though.

 

Am I the only one that uses the forum as a research and reference tool? Plus Jesus was resurrected, why cant a thread?

 

Gonna add something here.. I use diesel fuel for anything that needs to be cleaned out. Not too flammable is a big plus in book cause things tend to catch fire when I'm working on stuff.