Hydro Gear ZT 3100 "It just stopped"

[Opelman]

A Hydro Gear ZT 3100 came in sans mower with the "it just stopped". Well apparently it doesn't take special tools to disassemble one of these, this one is in rough shape. Pump pistons look OK in the upper right, motor pistons on the lower left are scuffed and most are not up like they should be. Broken springs under the motor pistons and damage from bits of spring steel improperly interfacing with rotating components. I have no idea why this failed in this manner. At least parts are available and it can be fixed.

 

[Kira]

A hydraulic pump? ...motor pistons?
It's cool, whatever it is.

 

[shurguywutt]

These are the transaxles for zero turn mowers. From what I understand, heat is the main culprit for damaging them. Was there dirt/debris on them? Fans in good condition? Oil levels sufficient? Air bubbles/gaps in the fluid.

 

[Opelman]

These are the transaxles for zero turn mowers. From what I understand, heat is the main culprit for damaging them. Was there dirt/debris on them? Fans in good condition? Oil levels sufficient? Air bubbles/gaps in the fluid.

Oil didn't look too bad in this one, I don't know about the rest. The transmission was removed by the owner and brought in bare and fairly clean.