1951 Cat Model 12 transmission lube and seals

That's a big job to replace the seals.
Nothing wrong with using NLGI "0" (corn head grease). Just the thing for leaky seals and can be continued use if that solves the leakage problem. I think he's reading the grease scale backwards, more "0's" means thinner. Do not go heavier as it will lead to channeling and no flow.

That's a big job to replace the seals.
Nothing wrong with using NLGI "0" (corn head grease). Just the thing for leaky seals and can be continued use if that solves the leakage problem. I think he's reading the grease scale backwards, more "0's" means thinner. Do not go heavier as it will lead to channeling and no flow.

Are you over filling it? I have a 1951 8T and use 80-90 in it. There are a few leaks but nothing pours out. Oil is cheap. Now if you are talking about the axles at the center of the tandems leaking. That is not a huge job. Just big stuff. Servicemans reference book Form. FEO30124-03 has the procedure. I would be concerned that if it leaks that bad, what is causing it. Are the pivot bearings loose? Or broken? Out board bearing gone? Lift the machine up and down, with the blade lifts, and watching for movement at that pivot point. The only movement should be pivoting. Axle Timken's should be loaded pretty tight. Reference rear axle in your parts book. The axle bearings and the outboard bearings carry the whole load of the machine.

I will check the bearings to see why it is leaking. In the end, I figure that a seal replacement--assuming nothing more than 68 years' usage is responsible--would allow me to go back to stock lubricants and likely outlast me. For the few hours we use this each month, though, we will keep the lube in there the same as what the last guy had before I bought it until we get out of our messy/wet NorthWest rainy winter weather. Besides that, it may take some doing to get the manuals😞

i used to make a mixture of grease and gear oil called Knuckle Butter. used it in the enclosed steering knuckles on 4wd trucks etc when the seals wouldn't hold oil any longer. now i use corn head grease because it flows better and stays put better also.

Hi, Brian Hart.
If you put the blade square across the machine and use both blade controls to lift the front end about 18" clear of the ground, you can then raise one side or the other of the rear of the machine by pulling on the OPPOSITE blade lift control to 'raise' that side of the blade. Have somebody watch the tandem case on the side that you are raising for any tilting movement in relation to the main frame.

The above trick works great for changing tires too.

Another quick and pretty reliable check is to stand back a bit behind the machine and check to see if the tandem cases and the rear wheels are parallel to the side of the radiator. If either or both appear to be 'toe-ed out' at the bottom, you have bearing problems in the tandem case pivot(s). Ignore this at your bank account's peril.

Just my 0.02.

Good explanation Deas. I had the same thoughts of what to look for but my old age brain wouldn't let me put it down. A loose tandem pivot is something you do not want to ignore.

Hi, oldbeek.
When I first got into operating graders, back when I was 20 years old, I thought to myself that they were the most complicated and yet delicate pieces of construction machinery that I had ever been on and so I sought to learn as much about them as I could. This learning about graders helped greatly to foster and cement in my young mind the notion that if we EVER stop learning, we are DEAD, at least from the neck up.

I have tried to never forget any of that learning. ALL of what I post here about these old girls comes from past learning and experiences 'cos I don't have any manuals on them.

I once worked with one man who had been on the same Australian-built 17K - equivalent to 99E - series blade for 9 years, 4 for the previous owner and then 5 years for himself as an owner operator. He complained to me one day that the machine was getting hard to operate and kicking back a lot in the control box.

I asked him if he had ever adjusted any of it to counter the wear. He replied that there were no adjustments. I spent 2 hours with him and the machine on each of the next 2 nights, doing the adjustments and showing him how to do them. At morning break the next day, he said, "This is a different machine."

And he had been operating it for NINE years???????????????????????????????? He could really handle the machine but he didn't KNOW it.

Just my 0.02.

One of the first jobs I had after hiring in a LA County was to try to rebuild the control box on a 99E. All the mechanics there at that time told me they take the gears out and replace them even they don't look worn. It helps a little. I picked up a service manual and read how to turn to a new area on the bull gear. They had never been turned to the next key. Had it done in 3hrs. The Forman said I couldn't be done already. The superintendent had me teach a class. Within 1 1/2 years I was the shop forman . At 5 years I was fleet shop superintendent. My previous boss at a large fleet said just ask if you don't know. If nobody to ask, get a book and read up.