Could be the shifter is out of adjustment. If you have to hold it in reverse it may be hitting the floorpan.
I had broken motor mounts and the engine moved back about 1 inch or better. I could see where the shifter was hitting the floorpan.
2013 WRANGLER SPORT 2 DR., V-6 ,AUTO,HARD TOP
)1994 Jeep Wrangler 2.5L, Bestop top
/w steel half door and slider windows
5 speed, 2.5" lift, 31" tires,rack lights