Well I figured out my problem, some additional troubleshooting showed that
the right side hydro unit (combined pump and motor) was running slow.
Input speed was the same at 3300 RPM on both sides but the right side maxed
out at 70RPM output where the left was over 100RPM. Changed filters and
fluid and checked the hoses. Found nothing. Pulled the transmission.
Eventually got the transmission open and found the the pump cam ring
cracked. Never seen one break like this. Parts on order, meanwhile the
grass continues to grow....
On Mon, May 11, 2015 at 9:12 AM, John Innis <jdinnis@gmail.com> wrote:
> Because the grass is tall, my mower is acting up and shop talk is flooded
> with mower questions!
>
> Saturday we a rare dry day and I was trying to get ahead of the grass.
> Got almost done when the mower started acting up.
>
> The mower is a circa 2000 Grasshopper 725K will less than 700 hours on is
> since new. This unit has twin "Gemini" (Eaton) hydrostat units, one for
> each drive wheel.
>
> The left side is working great, but the right side is running VERY slow in
> forward. It seems ok in reverse, but with the drive controls all the way
> forward, the left side is going MUCH faster than the right. Traveling in a
> straight line with the right control all the way forward, the tractor speed
> a much slower than it has been in the past.
>
> I checked the linkages, adjusted the neutral point, checked the hydro
> fluid and brakes, and found no issues. Fluid is full, belts are in good
> shape with no evidence of slipping. I lifted the frame up and confirmed
> that the speed difference occurs even if there is no load on the wheels.
>
> New filters and belts are on order, and will be installed with new fluid
> when they arrive, but I suspect they won't solve this issue. The thing
> that is bugging me it that the transmission seems ok in reverse, so likely
> not a clogged filter or slipping belt issue. Also seems like it's not a
> pump or motor problem, as one of these being weak would likely be weak in
> both directions.
>
> I have been warned that tearing this hydro down is not a job for a the
> home mechanic, but even if I get brave, I'm not sure where to look. This
> unit doesn't work anything like the hydros I have serviced in the past.
> Anyone on the list have any ideas or helpful troubleshooting tips?
>
> John Innis
> Cedar Rapids, IA
>
> --
> =================================
> = Never offend people with style when you =
> = can offend with substance --- Sam Brown =
> =================================
>
--
=================================
= Never offend people with style when you =
= can offend with substance --- Sam Brown =
=================================
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