alright now let me just start by saying that its most likely not what u guys think it is, haha and yes i have searched for my problem on here but i couldnt find a similar problem like mine. alright, so my 4 wheel wont engage. i have already checked the vacuum actuator underneath the battery tray and it get all the sucking power it could ever need. my transfer case engages and spins the front drive shaft. i have already replaced the line and the vacuum actuater and the steel line going to the front diff. the line is properly connected to the silver piece of metal that is attached to the differential to engage it. the problem is like it doesnt pull it out enough. like if i unhooked the steel wire and pull on it with my hand itll engage my 4 wheel perfectly but when connected to the steel line it doesnt do anything. it seems as if the line has to much slack in it or something. if anybody has any ideas about what could b causing my problem it would b greatly appreciated.
Thanks,
Nick
also its a 1997 blazer with a 3 button switch

 

Bumping this thread to the top because im having the same problem!! Somebody please Help!! Thanks

 

The actuator should be able to pull the cable 1/2" to 3/4" when fully engaging the front axle. If it isn't, then something is not right.

How far is the cable being pulled when the actuator is pulling on it??

 

It wont move at all on its own. I can get it to move about a 1/2" if i pull on it with chanel locks but its very very hard to move fells like its stuck inside the front diff?

 

In your case, jakem, you may have a problem inside the front axle. It should have some resistance, but not enough that the actuator cannot pull it. Have you tested the vacuum level at the actuator and compared it to straight manifold vacuum? It should be almost identical.

 

where the cable connects at the front differential you should be able to pull it the desired amount -reverse locking it up( Slip shaft should lock in). If this doesn't happen your issue is inside the front differential. Jerry