Hey guys I was having the same problem with the grinding from the actuator. I replaced the iwe solenoid and the driver side actuator becuase it was holding no vacuum I assumed this would fix it but once I got it back together it did the same thing. I have checked all the vacuum lines and they are fine, I have also checked the box behind the battery. The other actuator holds vacuum fine to, is there anything that could be wrong with the actuator besides the it not holding vacuum that would cause this problem. I am getting so aggrivated with this truck. I have tried everything I know and everything checked out the only thing I havent changed is the passenger actuator and it holds vacuum fine. Any help would be greatly appreciated. Also the truck only does it under certian loads and my 4x4 works great all the lights come on and everything. Thanks again for any help. Sorry for being so long.

 

Replace the check valves. They are there to maintain vac to the hubs under accel. If they are stuck open, you will lose vac under accel and get the dreaded grinding noise.

 

I checked the valves with a vacuum guage and they held fine could they still be shot. Also where can I get them at.

 

ttt

 

ttt