JD 797 PTO issue

[ctsjas]

I'm getting desperate and need help. I have a JD 797 with 485 hrs run time. It is not commercially used and well taken care of. After a short period of mowing (10 min) the pto starts to drop out. The blades start to slow and I hear the belt sqealing. If I slow down, the blades speed back up and I can resume normal cutting. A few minutes later, the same thing happens. I can still cut my yard (about 5 acres) but it is starting to take a very long time. Sometimes, the PTO will go 30 min to an hour without dropping out. I have put in a new battery but I have to keep it on a trickle charger when not in use to keep it charged. All my connectors appear in good shape. The battery voltage goes up to 13.5 at high rpm. The stator is putting out 36V at high rpm. I going to put in a new relay tonite for the PTO switch. If that doesn't work, I'm going try a new voltage regulator. Any suggestions? Thanks for reading.

 

[beenthere]

No suggestions, but hope you can zero in on the problem. Look forward to what you find out..

If the belt is squealing, then I'd look for that reason why. Loose? Or is something, like a bearing, giving resistance?

No sure how the battery enters into the problem, but you may know better.

 

[boggen]

I'm getting desperate and need help. I have a JD 797 with 485 hrs run time. It is not commercially used and well taken care of. After a short period of mowing (10 min) the pto starts to drop out. The blades start to slow and I hear the belt sqealing. If I slow down, the blades speed back up and I can resume normal cutting. A few minutes later, the same thing happens. I can still cut my yard (about 5 acres) but it is starting to take a very long time. Sometimes, the PTO will go 30 min to an hour without dropping out. I have put in a new battery but I have to keep it on a trickle charger when not in use to keep it charged. All my connectors appear in good shape. The battery voltage goes up to 13.5 at high rpm. The stator is putting out 36V at high rpm. I going to put in a new relay tonite for the PTO switch. If that doesn't work, I'm going try a new voltage regulator. Any suggestions? Thanks for reading.

idler pulley adjustment? idler pulley getting stuck?

stretched out belt? wrong size of belt?

is there any bearings going out? take belt off and see if anything jiggles (shafts to blades or hyd motor that runs the belt)

looking at... http://jdparts.com

is the "pto clutch" working like it is suppose to? seeing a couple wires plugging into the PTO clutch, i would assume, some additional internal parts and bearings to the pto clutch. that might be bad.

i am not seeing any sort of "switch / valving" for hydraulic lines that run to the hyd motor, that connects to the PTO clutch via a belt. so ya at the PTO clutch, i would think.

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you might try contacting a local dealer, and see if they could send you "electrical diagram" from a shop/service manual that shows color coded wires, and plugs, for your unit. so you could double check each wire for a bad wire possibly. with wire diagram perhaps being able to figure out how to create a quick test jumper wires from battery directly to pto clutch, with a fuse inline.