i found a forum that helped me figure it out. when these 4runners get stuck in reverse due to getting jarred or a sudden stop then you can manually move them out of gear by pulling the reverse light switch off the passenger side of the transmission and pushing the rods backwards. I did this and it freed up my gears.
5 speed stuck in reverse - Pirate4x4.Com : 4x4 and Off-Road Forum
"Anyways here's the break down, the 5th gear is heavy enough to "fall" and knock the tranny into reverse, with that the shifter is still in the (N) position therefor your not able to shift out of (R). So what you have to do is remove the (R) light plug on the side of the tranny *(Passenger side)* and in there with some small needle nose pliers you will see a metal tab, grab onto it and move it "back" *(towards the rear of the tranny)* till it can't move any further."