New Holland TC-25 clutch problem

[stevehull]

Out of the blue my TC-25 (manual transmission, 2,200 hours) has a clutch issue. Depressing the clutch fully does not allow me to go into gear as I hear grinding. It is as if the clutch plates are not quite far enough apart.

Looking underneath, I do not see an accessible clutch adjustment. Am I missing something? The hydraulic fluid is a bit low, but the clutch is fully mechanical and I don't have the hydrostatic transmission.

Thanks in advance!

Steve