Mowing Kubota TG 1800 series HST Problems

[MasterMechanic66]

I was working on a Hydrostatic on a TG series Mower today and I noticed that a lot of you have a problem with the factory sealed transmission. The problem that you encounter is runs fine on flat ground but has a heavy whine under load or pulling a hill. The tractor may pull at first but comes to a stop and is loud when it loads up. I have basically figured out what is happening. At or around 600 hrs the check valvues that are pressed into the pump body go bad. The constant slamming from foward to reverse or using the hydro to stop rapidly damages the seat in which the balls of the check seat into. You have two inside the transmission one is for foward and one is for reverse. Depending on how you operate it seems that the foward goes bad before the reverse will. I changed the oil to a 70 weight and made a slight difference but this is a quick fix. The pump body has to be changed and from my understanding the part is around 500 to 600. The manufactor tells people that these transmissions are a replace only and run around 1500. If your mechanic is a good one and clean in reassymbly then have them change the check body. These hydros can be repaired but it will not be inexpensive. The best way to help save your transmission is to slowly move to idle position and then reverse instead of rapidly going from one to the other. This keeps the seat of the check valve from slamming from one position to the other. If my spelling is off forgive me.