Zero Turn Hydraulics - single wheel works forward, but not reverse

[berky2755]

As the title says.....

My mower is a Ferris is5000z diesel (yeah, it's an older model). Last fall my crankshaft broke and long story short, I had the mower towed into the shop. They serviced it, but wouldn't touch the motor. I found a local guy to rebuild the motor, which is now working great. After we hooked it all back up, I had no movement on the left side. After much troubleshooting, and after removing the left hydraulic pump, I realized that the 'relief' / 'bypass' was underneath the pump (right side has it right there on top where it should be), and was loose.

So, After putting everything back together and closing up the bypass, the left side now will go forward just fine, however, in reverse there's no "power". If I lift it off the ground, the wheel will turn backwards just fine, but if there's any resistance, it won't move. What could cause this? as I see it, forward and reverse is nothing more than the direction of flow, so how can it move great in one direction and not the other? Everything was working fine last fall, so I don't know what would have changed with the pump.

 

[berky2755]

For anyone else that comes across this, for me it turned out to be the hydro pump. The bearing cradles (also heard them referred to as bearing slides and probably something else too) were worn down. The first time I took the pump apart, I didn't take the swash plate out, so I didn't see that these were bad. The pic is a bit worse than they were when I took them out as I was picking at it after the fact. So now I'm just waiting on the parts to arrive.