Milk Chocolate Tranny Oil

[GreeCguy]

Cold someone tell me what's happening here. Yesterday, I drained the rear-end on my father's old Case D tractor. The tractor was made circa 1950. I think the gear oil in the rear end comes from 1950. It is very, very, very think and heavy AND looks like milk chocolate. It doesn't smell bad like most rear end/manuel transmission fluid does. But it is in no way the amber/clear color. Does anyone have any idea as to what happened to this fluid over the years? I'm guessing when it was new, it must have been a 90 weight gear oil. Now, it has the consistency of warm tar. Any ideas?
Oh, by the way, if anyone needs any antique gear oil, I have 15 gallons

 

[reyjay1]

I do not know this specific tractor, but if it like most others, it probably got water in there, most often from the gear shift lever water leaks in, then over time algea grew in it turning it to the brown milkshake you got out.

Last summer drained a gear box out of a tractor that had been sitting out where it had stopped running for a few months, several gallons of clear water came out before any milky hydraulic fluid came out. All of it got in through the gear shift lever, just from rain. Most tractors the rear end and gear box is all one big sump.

 

[GreeCguy]

reyjay, thanks for the reply. I think you've hit the nail on the head as the tractor as sat outside in the weather for years. The gear shift lever is on the top of the transmission and the transmission was overfilled, (hence the 15 gallons). I had just run the tractor for about two hours before changing the fluid because I wanted to warm it up first. Perhaps, if I had drained it cold, the water would have been separted. I do have it in buckets now and will watch to see if it separates.
Since it sounds like you've been down this road, how do you think I could clean out the rear-end? I have the oil drained but haven't put anything back in it yet? Do you have any ideas? Thanks, Glenn.

 

[reyjay1]

Hey Greec, This is what we did-
Just go down to your nearest local farm and ranch store and pick up several 5 gal buckets of the cheapest hydraulic fluid you can buy or whatever it says it takes, and get back to the tractor and fill it up to normal level, it will take a lot. Run it at light duty for a few hours, and the fluid will have to be changed out again after just a couple of hours at the most, or sooner if it turns milky again. I think after one flush it should get most of the water out. If you can get a boot for the gear shift it will help a lot, we made a quicky boot with a funnel inverted and slid down the gear shift and then taped the skinny end around the lever. After the first flush keep a close eye on it for color of the fluid and that it does not get milky. I just read here : http://www.ytmag.com/case/messages/84611.html you may have a washable filter in there that you need to take out and clean also, look for the plate they are talking about around the drain plug, but if it is 1950's era probably doesn't have it, but check and make sure, if there is one it is probably gummed up. They were discussing this causing the 3-point not to go down it looks like.
In that thread he never really said what model he had, but the reply the last poster gave on what type of oil to use was:
/quote
Case manual recommends engine oil. 5 wt below 32ºF, 10 wt 32-60º, 20 wt above 60ºF.

Some folks here use 10-30. I use a general purpose hydraulic oil mainly for the anti-foaming additive.

Doesn't really matter, oils are much better than when this tractor was built.
/endquote

However it looks like it depends on model, it looks like some models used 80 or 90 wt gear oil. I would still flush with the cheapest hydraulic oil you can find and then get the correct oil in there.

Here is a good thread on the case 310, might want to ask around there, it seems Joe is a very knowledgable fellow on these Cases..
http://www.ytmag.com/cgi-bin/viewit.cgi?bd=case&th=84108

 

[reyjay1]

PS. just re-read your first post, here is a thread for the fluids for the '50s era DC-3
http://www.ytmag.com/cgi-bin/viewit.cgi?bd=case&th=83249

 

[GreeCguy]

Thanks again Reyjay. It's a good running tractor, it just needs a lot of loving right now

 

[GreeCguy]

Good evening everybody - just wanted to give you an update on the tractor rear-end. Did a total change yesterday. Drained the old oil. Filled the rear-end with ten gallons of used motor oil and drove around the yard for about half an hour. Drained that. Filled the rear-end with ten gallons of diesel fuel. Drove around the yard for about ten minutes. Drained that. Went to Walmart and bought 10.5 gallons of 85W140. I started pouring at 10 in the morning. Finished pouring the last bit at four in the afternoon. That stuff sure is thick! Drove the tractor up and down the road for about an hour. Now, the gears shift very easily, (they were hard to shift before the change) - tractor is running great! (Knock on wood). Thanks for all the help.
Glenn