What he means is when you turn the front wheels on his tractor in the forward direction faster he hears a light clicking sound. So the wheels can free wheel not providing the four wheel braking that you have with a mfwd.
I reread what you told him to do. I see you said have the wheels turning slowly and try turning the front faster. It make sense now. I thought he juat jacked up the front and tried turning it with the engine shut off, a clicking sound would be normal then.
I wonder if that hydro is supposed to perform like that? I think he needs more weight for sure now.