1990 Bronco, 302 4x4. reversing up hill, lift off gas feels like brake apllied. will not roll forward.?

Drive perfect in forward motion. Question is there an anti forward roll mechanism when reversing up a hill. For example I will reverse up my drive way, feels normal but when I let off the gas pedal the Bronco will slow to a stop and when the weight sifts back down hill it feels like a brake is applied, like seriously . It does it hard enough to jerk the vehichle. Engine will not stall. Place it in neutral and it rolls forward easy. Is the tension adjustble.