Details; Ford 195 with a loader. In reverse tractor surges and puts a load on engine. this happens on level ground without any extra load on it. Barely wants to move( 7/8 throttle). Put the bucket down to back blade and it takes everything to move it. A lot of vibrating and shaking under/in tractor. Go forward no problem, even when pushing a load of dirt( no surging or vibrating). When backing up i did notice the shifter lever moving back and forth as the tractor surges. I checked the fluid and was only 1/2 pint low, which I added before I tested. No change. The rear does not appear to be disconnected from the frame but it started raining so I didn't investigate further . No parking brake issues either!
Things I should be looking for??
Hydro unit burnt out?
Dirty fluid and valve /passageway blocked? Fluid change? Fluid has less than 200 hours and didn't appear too black. Tractor leaks thats why it was low.
Something broke? Mount related
Could it be the rear and not the hydro?
Any and all suggestions would be appreciated.