I recently bought an '87 D150 3.7 liter 6 Cyl. with auto trans. I suspect that I have a bad neutral switch and/or that it has been by-passed for some reason because the truck will not start in "P" but you can pull in down into any other gear and it will start. The big problem is that when I park the truck, it still wants to roll. It sort of feels like the shifter is not going all the way over into "P". Could this be some sort of "linkage" problem? Is this sort of thing very hard to fix? Thanks for any help or comments.

 

Just a little update. I figured out that the problem was linkage related.

 

Sometimes those plastic bushings in the shft linkage wear out or break.