520H throttle requirements

[Arthur England 5]

Greetings,

In the 520H user manual it states "Always operate the tractor with the throttle control set at full speed..........................Operatng at less than full throttle may result in extensive transmission damage and poor performance* (some text left out as I cant cut and paste from pdf file)

 

My question is why would it damage the transmission?

I can think of two possibilities 1) that the hydro does not get enough cooling if the fan is not running at full speed. 2) that the charge pump on the eaton 1100 does not ensure enough oil flow at low speeds.

The reason that I ask is that on other machines that are under light load, I would reduce the engine speed and go for a higher ratio but this would not sit well with the 520 manual

I would not consider this if the machine was working with the PTO as you would require the power, but for low speed manoeuvring  full throttle is a bit frantic.

 

Cheers Arthur

 

[lynnmor 7,354]

To do a specific operation, running at half the RPM will require double the torque.  Think of the load on each vane at various speeds. 

[Ed Kennell 38,687]

For low speed no load maneuvering, I run all my engines at idle.  That includes Kohler and Tecumseh singles and Kohler and Onan twins.  Never had a problem with the Eatons or Sundstrands.    

[WVHillbilly520H 10,374]

Bought my first 520 brand new 20 years ago, I have run it at what ever engine speed I deemed appropriate doing different activities, but most anything being run off the PTO I run at WOT but using the dozer blade or rear blades, or York rake bit above idle to half throttle, and yet to have issues with the hydro or engine overheating, Jeff.

[JAinVA 4,623]

Thanks for the observation Jeff.I tend to run my engines at way less than WOT on my 1100s unless I'm blowing snow.I have not had any issues but I'm glad that there are others who have put more hours on their machines than me who do as well!

Edited September 18, 2018 by JAinVA