rmfarm - 2/7/2026 13:01

Recently purchased an old Cat D6C 76A series dozer for some occasional work around the farm. I have an owner's manual. It and the previous owner both say to use 30wt engine oil in the transmission and hydraulic system, and to use 50 wt engine oil in the final drives. It is a powershift, if that would make a difference. Would you continue to use engine oil throughout, or would there be better choices now like Case Hytran for example. And maybe 80-90 for final drives. What about 15-40 rather than the single viscosity. I've talked to two different Cat repair shop and have gotten different answers. Thanks for the help.