what would effect my tranny shifting down from 3rd to 2nd or when I'm slowing down 2nd to 1st,is it a vacuum problem or something more serious
hard shifting noise and actual thump on 1990 Mercedes-Benz 420SEL
There is a small vacum hose behind the engine block and it can come off causing the problems you specify. You'll have to look behind the block using a flashlight and it's near the top. If it's off reconnecting will correct the problem. You have to get some long needle nose pliers (2) with angles to get to it and reattach.