I was using my Mahindra Max XL26 yesterday to push and lift brush to be picked up by FEMA. After pushing brush forward in low speed gear 4 for several minutes, the tractor failed to move when placed into reverse. After shifting into different gears using both High and Low, I discovered that the tractor will only operate in Low and then only in 1st and 2nd gear. Bucket hydraulics work fine and fluid levels are good. Transmission shifts smoothly through all gears and easily changes from Low to High. Any thoughts?