I've plowed with both my Massey 12G and my Massey 12Hydro. The hydro has only a single speed rear end, and I found I was constantly making small adjustments to it to try and keep the speed I wanted (top speed is around 9mph, not plowing there) as ground conditions changed. One of my sons was really bad about being heavy handed with that hydro and would start spinning the wheel at Warp 9 when it would start to slip. With the gear, I just selected a speed and off we went, no need for adjustments.
I also understand that hydros will build up heat when used for extended periods at high load, such as plowing a field. I suspect the problem is worse with a single speed hydro that a dual speed unit, but I don't know
I am a HUGE fan of hydro, but they do create a lot of heat. My Bush Hog JBI with the Wisconsin TJD engine, it's hydro got pretty hot during my plow day. I am going to try & put an oil cooler on it before next year. It is a single speed rear end, kinda geared between a normal Hi/Lo. Hard pulls with a single speed create higher pressures, thus more heat. Almost all hydro's create more heat under plowing concitions than the factory cooling fan can deal with.
Howards, I'm looking forward to trying out my Ford 165 for plowing when it's done as it's the biggest GT I have but the foot control hydro doesn't seem like it will be ideal. I guess I won't know until I try tho, it may just be one of those personal preference things
I've also always been a HUGE fan of foot controlled hydro. But after 2 years of plow day with foot control, I've found it is NOT the hot setup for plowing. One's foot/ankle gets very tired & achy from holding the position. Hogzilla will be getting a hand control rod along with the foot pedal before next year with a friction hold system of some sort. The Bush Hog HD-12 was built with just that. In the pic below, you can see the handle shaft connected directly to the pedal. Just above the pedal you can see a bolt above the pedal's shaft. The bolt pushes against some sort of composite material, which in turn presses against the shaft to hold the position. Tension is simply controlled by turning the bolt in or out.