Repairs Grasshopper 721DT

Jjracoon

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I was mowing just fine and stopped the mower. When I got back in it started fine but no movement. Any ideas why?
 

Jjracoon

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This mower has a single hydro and I show two belts in the back behind the motor and they seem to be OK. Is there another belt I am not seeing?
 

shiftsuper175607

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This mower has a single hydro and I show two belts in the back behind the motor and they seem to be OK. Is there another belt I am not seeing?

I am not there..so I'm not seeing
You have a main belt from the engine...I would check it
 

Jjracoon

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I am not there..so I'm not seeing
You have a main belt from the engine...I would check it
I see there is a small belt running vertical on the back of the hydro area. I will start it up and see if it is slipping there. Thanks for the help.
 

173abn

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on a 721D isn't there a shaft from your pto that goes to the hydro pump?...russ
 

NWGH

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I wondered about that...looked at some parts diagraph and could not tell.

I am a new GH owner (623T) and just joined this forum, but as I understand it, all T series grasshoppers have a dual hydraulic pump that is directly shaft coupled to the engine, so there is no belt involved in powering the transmission. The pump feeds the wheel motors via direct hydraulic hose connections (visible under the seat). The two belts at the rear of the engine are indeed for the PTO, but they should not affect problems with movement - they would only provide power to the mower deck or other attachment.
If the engine starts and runs, then the pump should be getting power. If the pump is being powered then a problem in a control arm linkage, or a loose bypass bolt on the side of the pump body, might keep one wheel from turning, but with either of those causes it would be strange to have both wheels affected at the same time. The only thing that occurs to me as a cause for both wheels inoperative would be if the shaft coupling is slipping or broken? As noted I'm no expert, so I'd be inclined to go to the GH website and use their Ask a Technician service... Hope this helps.
 

cpurvis

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Or if the pump itself has given up the ghost.
 

Jjracoon

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I am a new GH owner (623T) and just joined this forum, but as I understand it, all T series grasshoppers have a dual hydraulic pump that is directly shaft coupled to the engine, so there is no belt involved in powering the transmission. The pump feeds the wheel motors via direct hydraulic hose connections (visible under the seat). The two belts at the rear of the engine are indeed for the PTO, but they should not affect problems with movement - they would only provide power to the mower deck or other attachment.
If the engine starts and runs, then the pump should be getting power. If the pump is being powered then a problem in a control arm linkage, or a loose bypass bolt on the side of the pump body, might keep one wheel from turning, but with either of those causes it would be strange to have both wheels affected at the same time. The only thing that occurs to me as a cause for both wheels inoperative would be if the shaft coupling is slipping or broken? As noted I'm no expert, so I'd be inclined to go to the GH website and use their Ask a Technician service... Hope this helps.

I appreciate the response. Having to work on other stuff I put this on the back burner till today and will use your info to attempt to remedy. By the way, what is the small belt that is behind the hydro for then?
 
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