I run a Nissan Patrol PTO gearbox close coupled to a hydraulic pump, that powers my Milemarker 15000lb hydraulic winch. I have recently purchased a 3:1 planetary gearbox to increase the output speed of the PTO box and hence get greater flow to the pump and then winch motor.

Below is the data I have discovered and the results regards line speed. The PTO is nominally rated at 18kw.

The Nissan PTO has two fixed ratios, forward is 1180rpm for 1000rpm engine speed, and reverse is 1530rpm for 1000rpm engine speed. The nissan PTO runs off the gearbox, unlike the Toyota that runs off the PTO. This design is limiting as to increase line speed you have to increase engine speed as opposed to selecting a different ratio or gear on the Toyota. This limiting factor is the reason I am soon to upgrade the drive speed to the hydraulic pump by a ratio of 3:1 using a suitably sized planetary gearbox running in reverse.

The hydraulic pump is rated at 0.032L/rev. At the existing setup and at engine idel speed of 500rpm, the pump runs at 554rpm, and delivers 17.73lpm to the winch motor. Based on the first drum circumference and Milemarker specs, this results in a slow speed retrieve speed of 3.6m/min. This speed does increase as the drum diameter increases, and does not affect the loading detrimentally due to its design capacity.

The new speed will be 3 times this, so approx 10.5m/min at 500rpm engine idle speed. Increasing the engine speed directly increases line speed, hence I will need to do a slight change in hose size to uprate for the increased flowrates. I have not checked this out fully however suspect the pressure line will uncrease from 3/8" to 1/2" and the return to either 5/8" or 3/4".