# lifespan of hydraulic stump grinders,(like rayco)



## MOE (Apr 2, 2010)

I'm looking around at used self propelled grinders. How many hours are you guys getting out of hydrostatic drive stump grinders,(rayco, morbark, bandit)? Does the power at the cutting wheel get weaker as the pump and drive motors get hours on them,(like 1000 or more)? How about problems with leaks? does the hydraulics seem to dampen the vibrations transmitted back to the motor? Thanks


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## Oly's Stump (Apr 2, 2010)

I have owned 8 different grinders now and some are belt and some hydrostatic. Myself I would prefer a belt machine. I see a h.p. loss in the hydrostatic units. In my book it don't take much to check the belts and adjust. That cover should be taken off and cleaned out weekly anyway.


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## MOE (Apr 2, 2010)

Oly's Stump said:


> I have owned 8 different grinders now and some are belt and some hydrostatic. Myself I would prefer a belt machine. I see a h.p. loss in the hydrostatic units. In my book it don't take much to check the belts and adjust. That cover should be taken off and cleaned out weekly anyway.



I realize the power loss. A rule for hyd loss is 5% at the pump and 5%at the hydraulic motor. I would still prefer a belt but when looking at used ones, I can't rule out a good deal on a hydrostatic. I've also wondered if the hydraulic drive would isolate the engine from the vibrations a bit more and maybe have more engine life?????


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## Bigstumps (Apr 5, 2010)

It does isolate the motor from the shock loads but that isn't really where you see problems anyway - it is usually down at the cutter bearings or in Polychain and sprockets. 

I've cut with the tow behind hydros and they are no where close to my belt drive Vermeer, not even close!! And they were way more expensive. I'd be afraid of what dirt in the fluid would do to one.


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