My truck makes a ratcheting sound when accelerating in 2wd... I put it into 4wd, it stops.. I am aware of IWE and solenoid issues... however, my truck is a manual shift 4wd.. (no button... must shift lever into 4wd) If I go into 4wd, then back into 2wd, the noise will subside for a very short period, then return... almost sounds like a hub trying to engage.. Even though the 4wd is manual shift, are there still vacuum lines to engage the hubs? This truck doesn't have a push button, a solenoid, ect... it is all direct shift...

The truck has a 5.4 with automatic tranny...

Thomas