What would cause the car to jump when shifting into reverse. on 1996 Oldsmobile Bravada

All other gears are smooth and it happens only in reverse

Asked by for the 1996 Oldsmobile Bravada
Check the motor when putting it in reverse, it will probably jump because of a motor mount.
No reply.
Thank you it turns out it was the motor mount and i bought the car from a lot that didnt do a tuneup before it was sold so i then replaced all fluids and it runs great