My DB 880 selectomatic keeps getting water in the hydraulic fluid/tranny fluid. I figure it is going in through the gear shift boots. I am trying to flush out the water. With out disassembling everything. I am wondering what I should do. The owners manual states the tranny takes conventional oil. 20W40 I think. However I have a loader on the tractor. I run TDH hydraulic transmission fluid. A tractor mechanic recomended it. Can I run a couple pails of 20W40 through it to flush it out? It is cheaper to buy. Some one also told me to run regular transmission fluid, it flows better, doesn't freeze as easy. Right now I have to put a heat lamp under the trans to thaw the tranny before using the tractor.