B1750 starts but won't move, just makes grinding noise when clutch is let engaged.

[Darkhorse777]

I bought an older b1750 HST 4x4 a few months ago. I had been using it with no problems and backed it up to my tiller one evening, thinking that I would hook up to the tiller in a day or two. Although I had no problems when I parked it, I went to get it and hook up to my tiller but after I started it, it just wants to sit there and make a grinding noise. No previous problems and the hydraulic fluid is at the correct level. I made a short video of the problem. Sure could use some insight on this. I have a video made.

 

[jaxs]

Throw-out bearing failure normally prevents disengaging clutch which drives propeller shaft that in turn drives transmission and pto. On standard shift,geared tranny the tractor would continue to move along if it were in gear and clutch pressed.
To start narowing down I would see if propeller shaft is turning. I "THINK" a plate located between your knees can be removed to allow watching shaft while sitting in seat with tractor running. If I recall corect the transmission filter sticks up through a hole in said plate. If that shaft continues turning as HST pedal moves throw-out isn't stopping tractor from moving. Notice on the same shaft,just before it enters tranny there's a flexiable ball about 1/2 size your fist that acts like u-joint. If that ball goes bad the shaft from ball to tranny stops turning although shaft from ball forward to clutch is turning.
All the while engine is running LOOK BUT DON"T TOUCH SHAFT,not even with sticks or tools. It will gittchee in the blink of an eye.