Behind door number one

[Tchara]

I just purchased a CJ3a and have begun the process of getting it road worthy. I popped the cover off the tranny, and this is what I found. (see pic) I viewed a Youtube video, and the guy said they were notorious for getting water in the main gear housing. Mine is no exception. There is no gear oil, but water at the bottom. I want to fill it with somehing to clean and re-lubricate the gears. They seem to be stuck. The large gear slides back and forth, but that's all I can move. The shifting forks rotate freely, but won't slide on the pins. I that normal? What type of fluid would be best to clean the transmission. My options are, tranny fluid, hydraulic oil or diesel.

Anyone  have ant success with these, or can you recommend some thing else?

[PercyUK]

 I have to be honest yours looks better than mine did so I had to replace the internals with a rebuild kit. At a glance it looks like it may be OK. I would use petrol and a brush to loosen and remove all the old rubbish and then new oil. There is a risk that some rubbish may remain between some rotating parts but if you are looking for a temporary fix that should work. In the long term you may need to strip it for a deep clean and oil seal changes. (after all the old oil must have gone somewhere). Good luck

[Rus Curtis]

I believe the reference Percy made about "temporary" is key. 

Regarding safe long term operation, it's not what you can see, it's what you can't see that will come back on you.  There are roller pins between the main shaft and main drive gear (input shaft).   Then there's a whole other collection of roller pins on the counter shaft under what you see in your image (in the bottom of the transmission). If you started with no oil and just water, ASSUME the damage is worse that what you see.  Take it apart and then you can better determine what needs to be done.

If you want to do the band-aid fix a thin lubricant like transmission fluid (echoing you'll circulate whatever's inside all around), you may get a little more use out of it.  Here I must stress the inherent danger of using gas to clean.  Better to use something less combustible.  As far as after-clean use?  I can't guess how long that would be.  But at some point you'll have to pull it again and rebuild.  And I agree, if there's a leak, a thinner lubricant will leak out faster and make a bigger puddle.

Since the transmission and transfer case share oil, it would be wise to pull that and also inspect.

There are good rebuild guides and videos to assist.

[Tchara]

Hi all
Thanks for the advice and info. I didn't know the transmission and transfer case share the same oil. I dropped the plug on the transfer case, and got water, but also oil after the water ran out. I plan on getting transmission fluid to fill both the trans and transfer case, and let it soak for several days.  If i fill the trans from the top, will it flow to the transfer case, or should I top off the transfer case separately?

[SteveKfl]

IMO... Separately, and if it were mine, I'd pour just some in equal to previous amount of water/oil drained, wait, and then drain that too, trying to make as much water and sediment come out before filling to soak, and then later after soaking, trying to spin everything.  T-fluid might show leaking seals too.