Okay well to start. I have replace the switch on the Transfer Case, The Dash Switch, And The Diaphragm under the battery. I have also replaced all the vacuum lines and checked out all vacuum. Great vacuum power! Now the catch to it is, when I put it in 4wd the Diaphragm pulls back and the cable slides right out! There is quite a bit of play between the hole on the diaphragm and the cable. What the hell would be wrong? The first time I found the problem I went back to the parts store and this one does the same thing! Any suggestions????

 

I'm trying to picture the "play" that you are talking about...Maybe the clip that holds the other end of the cable in the diff broke.
If you pull on that cable can you get the Diff to lock up?

 

sorry I was not clear. The end of the cable that goes into the side of the vacuum actuator. The little clip is there but it is not "catching" the cable to pull it back when 4wd is engaged so there for it will not go in to 4wd because the cable is not being pulled back by the diaphragm. I can manually pull it myself....

 

Sorry if this sounds dumb but are you sure the flat end on the clip is in the notch of the actuator? There is a notch in the shaft part of teh actuator that the springy clip has to sit in so it can catch the tip of the cable.

 

Does anyone know where to buy that springy clip which is found both on the vacuum actuator and also on the end of the differential cable? Thanks for any leads, need a part number, I ordered what was believed to be the part several times from GM and it was the wrong part each time. Thanks!