I've got an 04 STX 4.6L 4wd. Been hearing buzzing from the front end. and occasional clunking. The four wheel drive does still engage and work properly and pretty damn good for that matter. also I should mention that it is NOT shift on the fly, it is a lever on the floor. Based on reading the 10billion threads on this forum and others I'm Pretty sure its the actuators not doing their job. theres some grinding going on still after I replaced the solenoid. My question is.. is it possible to have actuators fail if the solenoid is still good? And I guess the most important question to ask is if this sounds like an actuator problem to u all. Any suggestions are much appreciatied, thanks guys.

 

jack the front 2 wheels off the ground. in 2 wd engine off, spin each wheel by hand and see if axle turns w/ wheel do both sides. now start the truck up "motor running" in park 2wd. spin wheel s again. axles should NOT be turning! If an axle is turning with the wheel motor running, Then that actuator is bad or not getting any vac to it.. hope this helps. also check vac lines for leaks or holes.

 

Vac to the units axles don't spin! No vac to the units (leaks or bad unit) axles spin w/ wheels

 

Thanks guys I will try that and update on the results