Recently purchased a late model (1971-72?) TD15B power shift. Doing a full service on it in the next few days. What transmission oil is recommended? I have read people using SAE 10w engine oil, SAE 30w engine oil, and Hy Trans or equivalent. So which one is correct?
After a quick search on here, and other places, it seems like non-detergent 10W engine oil is the proper answer. Some guys have got along fine with 30W, but it seems like Hy-Tran might not be the best choice for the clutch discs. Here is a fairly recent thread, and an older one. Both call for 10W. HeavyEquipmentForums HeavyEquipmentForums If it was mine, I would be locating a operator's manual, seeing what was recommended when it was built, and going from there. If it says 10W, I'd be running Cat TDTO 10.
From the IH 175C / TD15C book.
It says for "all temperatures" you can use Hy-Tran. Problem is, today's HT is NOT the same HT from 40 years ago. At the end of the day, that tractor more than likely had regular old transmission hydraulic oil for most of it's life, so it probably doesn't matter what you put in it at this point. I still think Cat TDTO would be your best choice, and you can also use that in the hydraulics.
Previous owner (only owned for 4 year and it sat for 2 of those without being ran) said the guy he got it from ran SAE 30 in everything. SAE 10w seems to be really difficult to find. Napa has Cat T0-4 10w hydraulic oil.
You need to take a road trip to a Caterpillar dealer for your oil. This winter, I bought 55 gallon drums of it for about $750. It looks like Napa TO-4 is about $20 per gallon, so Cat might even be cheaper.