Farmall Cub

I'm finally getting around to replacing the transmission fluid in my '51H, which I bought five months ago. I plan on draining the old, very black fluid out, then running 5-6 gallons of kerosene or diesel in it for 15 or 20 minutes before draining that off. Here's my question for the smart folks on the Forum:

What do y'all use in your transmissions? I'm thinking about using Warren® 90W mineral gear oil, API GL-1. What are your thoughts?

Thanks!

Jim

90wt gear oil, I prefer one that is EP (extreme pressure) rated. An H that only get light use tends to condense water in the transmissions, even when stored inside. There will be about a quart of old gunky oil in the belt pulley housing if you have one. The only way to drain that is to remove the belt pulley housing and wash it out. it is splash lubricated from the transmission, but if you remove it and clean it out it needs to be refilled when it is reinstalled to have some lubrication at the beginning. I do not know about all of the H models, but my 41 has a drain plug at both the front and rear of the transmission, and both must be removed to get all the oil out.

I drained and refilled the transmission on my H for the first time last weekend. I was expecting around 6 gallons of gear oil, but instead I got 2-1/2 gallons of stuff that looked like butterscotch pudding. I hope I didn't burn anything up running it that low. I refilled with 6 gallons of 85W140.

Thank you John and Urbish, for the quick replies. Yes, John, I do have a belt pulley, so I'll do what you suggest. My H does get very light use, but if the condition of the transmission oil is like the condition of the engine oil, it needs changing for sure. Unless someone chimes in with a reason for me not to use the Warren 90 weight mineral oil, I'll be going with that. First things first, though. The H, along with my CC 106, gets a new "barn" this next week - a metal 20' x 20' building, but it will be my new barn. Once that's in place, I'll resume working on my tractors. I can't wait!

If this is the oil you're talking about, it should be fine.

Hi Don, thanks! Looks good, other than the word "Ford"! Yeah, I think that is what I'll use, although I found the same oil, branded slightly different at Agri Supply (a local farm supply house, way better than Tractor Supply). Here's their link: https://www.agrisupply.com/90w-gear-oil/p/16324/

As far as I can tell, it's the same product, just in a different container - 12 bucks cheaper for 6 gallons though.

Again, thanks to all for the input!

Jim