85 d100 2wd auto. Truck makes a weird thud/knocking noise especially when turning left at speed (pretty much any speed ) and sometimes when going straight. The noise sounds like a bad shock rattling when going down a rough road or exhaust smacking the frame. It also seems to be speed dependent...the faster I go the more knocks/thuds. New front rotors, bearings, calipers and pads. All shocks seem to be tight and right. Motor mounts look good. Tires are new. Doesnt seem to be any play in A arms or any front end parts....all seems pretty tight. Any ideas?

 

Have you checked the CV joints? Check the boots for cracks and leaking grease.

 

2wd truck. universals look/feel good. makes same noise in any gear or in neutral. when I first take off in the truck the noise isnt noticeable, until I put about 1/4 mile on the truck then it starts. the cab seems to amplify the noise, when i open the door and lean out going down the road to try to listen, the noise is less.

 

Double check your motor mounts and transmission mount too. I would really think that it's the driver's side mount because of the turning left thunk you mentioned. My old mounts looked fine until I hit a deep hole and the old rubber just tore apart.