Hello. I just found some gear oil that I think will work well in the cletrac transmission, I have a 1942 AD. It is from AGRI SUPPLY Company. The oil is a GL-1 90 gear oil that should work out to 50 weight motor oil. Item number 16323. this oil should work well with the bands. ZIMMERMAN CLETRAC told me of the company. Hope this helps. Phil
AGRI supply is the same type of company as Tractor Supply they just carry this oil. Phil