I bet it is a linkage adjustment. For some reason your not "reaching" reverse. It is the last position in the movement of the the lever on the side of the transmission. Before you do anything drastic, jack up the reared high enough to get under the car, disconnect the shifter lever at the transmission and make sure the wheels are off the ground and the car is stable, then start the engine and manually move the shift lever on the side of the transmission to all the positions. I believe all the way back is reverse. I. want to remind you this is a very dangerous procedure if the car is not stable when lifted. I recommend wooden blocking like 4x6 laying flat on top of each other under the axle. This is much more stable than jack stands if you are gong to start the engine, get under it and putting it in gear. Also make sure your feet are not near the rear wheels when you put it into gear. Jeff I do not mean to insult you with my safety briefing but I spent the better part of 41 years training young people in the army to be safe first and mechanics second. If my recommendations do not fit you maybe someone else can use them and you merely provided me with the opportunity to help them.