On my '87 240 DL, the backup lights come on or go off depending on the shifter being held toward Park or rearward toward Neutral. There is about 1/2" of movement at the top of the shift lever in each gear position. I tried to adjust this problem away by shifting the ignition lockout switch but quickly realized that the play far exceeded the adjustment range. I assume there is wear in the linkage to the transmission. Before I start messing with the linkage I'd like to know if someone has experience with this. Where is the play likely to be originating? I assume that it must be wear in bushings, pins, or holes in the linkage. Hopefully this is not a replace the hole lever unit situation. Thanks.