If it runs fine I'd check the drive belt, associated pulleys, tranny fluid for quantity and quality. That's assuming your tranny has the reservoir and drain/fill plugs.
#3
rmancini
Mine has been doing the same thing for some tome now, but only when hot and with the blades engaged.
It gets so bad that the mower stops and wont move until I disengage the blades.
The belts and hydraulic fluid level are just fine.
Same conditions with yours ?
Rich
