John deere 4400 with Hydrostatic drive will only go 6 mph in C range.

[Eddahl11]

Hi all, I bought the tractor used and already had around 6k in repairs into it. (didn't know what I was buying) Anyway, the specs on the tractor says it should go 15.5 mph in C range and it's top speed is only 6 mph. It doesn't seem to be slipping at all when going up and down slopes or dragging the horse pen. It just doesn't go very fast at all. Can someone please give me an idea what may be wrong? I have checked fluid levels, changed the filter and oil. It just seems like it's not getting the pressure needed to drive the transmission gears fast enough.

Thanks all
Ed Dahl

 

[oldnslo]

Ed,
In hydraulics speed is a function of flow while force is a function of pressure so if it is climbing hills you do not have a pressure problem. First thing I would check is to make sure you are getting full pedal travel in forward. I.e. look for something obstructing the linkage or pedal travel.

 

[bigdeano]

Does it go the proper speed in the other ranges? That might give a clue as to what's wrong.