View Full Version : Help with Grasshopper Hydraulics

08-25-2001, 12:16 PM
I have a Grasshopper 721 Diesel. The Kubota diesel seems bullet-proof but my power at the wheels is weakening. The machine has 1600 hrs on it. Has anyone sucessfully rebuilt the Gemini transmissions in one and will it restore the original power ? I know that I can get the parts and was just wanting to know if anyone has rebuilt theirs. My machine is just for home use and was bought used. thanks, 22R

08-25-2001, 04:37 PM
Yeah, my 721 feels similar. Piss poor design if you ask me. J. Thomas sells rebuilt Gemini hydros for about $650 a side. I wish there was a cheaper way. That would be great if someone had a little info on rebuiled these.

08-26-2001, 10:26 PM
Keith, What do you mean by poor design ? I don't know what to compare it to. What wears in the Gemini and what wears or does it wear, in say a Scag or a Dixie Chopper ? I know that you can buy replacement parts for the Gemini, I just don't know what wears, Impellors, Vanes, O-rings ???? Later, 22R

08-27-2001, 12:10 AM
I believe they tend to leak down around O rings, seals and such. Grasshopper went with an optional "G2" system that uses pumps and seperate wheel motors. They tend to have less problems. The original Gemini transmissions tend to work poorly as they get older, where we have not experienced any problems like that with the Pump/Wheel Motor setup on other mowers.

As far as what really needs to be replaced in the Gemini, someone could give you a better answer than I could.

09-01-2001, 10:03 PM
22R , The Gemini drive system uses balls about 1" in diameter that turn the drive assy. These balls wear thus letting oil leak around them causing poor performance. Also there are rubber seals under the valves under the cover of the main input side that could be leaking. I would suspect some of both. Grasshopper can rebuild your transmissions if you'll send them to the factory. Their number is 1-620-345-8621 , call the service dept and see if they can help.