I was out on the lake last night and after getting stuck in 6" of hard packed snow, I discovered that my 4WD is not engaging.

When engaging 4WD, I do hear 2 clicks several seconds apart under the dash. I've checked the lines from the solenoids to the actuator and did not find any cracks. I have not checked the lines for vacuum yet but...

Last winter while engaging 4WD, I heard a load POP from the front end when I was turning the wheel and engaging 4WD. Ever since then, I haven't been sure if its been engaging but it was confirmed yesterday on the lake.

Based on what I've read, I assume its either the actuator or the shift fork. I went under the truck and had my wife engage and disengage the 4WD. The actuator was trying to move (maybe 1/16" inch) but the shift fork wasn't moving. Does this mean the shift fork is bad (frozen) or does this mean the actuator is bad (not enough power to move the fork)?

 

I hosed everything down with penetrating oil and moved things around. I tried removing the actuator but couldn't, even after removing the c-clip. I am getting about 1" of movement now which is marginally better.

How much movement should there be at the actuator and if 1" is normal, does that mean I have a bad shift fork?

 

If the splines arnt matched up the actuator won't engage all the way unless you move forward alittle bit or you reach back and turn the drive shaft try that while your wife shifts it into 4wd. And you can shift it into 4wd and jack the front end up and spin the tires by hand if they turn backwards of each other the front end is engaged if not something may be wrong with the fork.

 

Well, I was screwing around with it today and a few choice hits with a hammer broke the actuator. So...after pulling the rest of it out, I found that the shift fork was locking the axle and it was the actuator that was not working. An easy actuator replacement later and my 4wd is working again.