Engine/Transmission (1998.5 - 2002) truck bucking

[TReed]

my buddy hit a deer lastnight with his 99 2500 automatic now his truck is bucking any time he goes up a steap hill or a moutian the bucking is light other times HARD when his truck is bucking the rpm's stay the same dont drop or go up. if you guy have any ideas what to check it would help



thanks travis