Tractor mounted mower hydraulic problem?

[Oldgravesendiansgroundsma]

I use a Ransomed mounted 5 hydraulic mower for fine cutting a cricket & football (soccer) field here in the UK. It has 5 six-blade cylinders powerd hydraulically from a PTO powered pump.

One of the reels hardly spins when lowered for cutting, but with the mower raised it spins very fast. It spins in reverse both raised and lowered with no problems.

Is this a hydraulic motor starting to fail? Or something more involved (bearing failure).

Attached is a stock image of this mower so you know what i'm on about!

 

[Redneck in training]

First I would look at shear pin. It is possible that the motor is running but the shaft is spinning inside the coupling under the load. When the PTO is stopped the motors should lock up. If you can turn the cylinder by hand the shear pin is broken.