So my 4WD isn't working. Although the light on the dash does come on, but no front power. Glancing underneath i can see the front drive shaft turning, but I wasn't getting power to the wheels. Is there anything this could be besides a broken gear in the diff?

 

Fork that pulls the sleeve over the axle end, or the sleeve might be broken, light coming on says your vacuum actuator is probably "working"... I'd take the actuator off and see what is going on inside before opening the diff.

 

I thought the light was connected to the xfer case. Probably vacuum leak at the CAD. Check the hose and elbow there.

 

Nope, switch for the light is actually on the front axle, and the plunger for it is pushed in the the rod from the vacuum actuator. The fork in there is only held in place with a couple snap rings, so, it's entirely possible one, or more... have broken, and everything works, but, the fork just slides on the shaft, instead of moving the collar.

Careful with the bolts on the cover though, they are notorious for breaking off, instead of breaking loose.

 

Everything looked intact, although I didn't check to see if the actuator moved the fork or not. Once the collar is engaged, spinning the tire should turn the driveshaft correct?

 

Yep. Can you slide the fork around on the actuator shaft at all?

 

Posilock makes a bypass cable for the vacuum system. 99% of the time the vacuum system is messed up. And you can pull the 4x4 in without going in reverse like you do somtimes with the vacuum.

 

Figured it out. U joint busted on the left shaft. Took most of the shaft with it though. Is the the Front shaft standard? I see quite a few options looking online for parts.

 

You need both shafts(inner/outer)? I'd look at sourcing that from a jyard.

 

What axle? Dana 44,60?