2000 Blazer 4.3 4x4 3 button switch
i was getting a bad humming sound when i would slow down after a little jaunt on the highway, figured it was the front tires trying to engage, would go away after hitting 4hi, then back to 2hi, after looking into it and seeing it could be the vacuum switch (on top of transfer case) i bought a new one, today i took the old one off, sure enough the ball valve was stuck in, so i put the new vacuum switch in and now no 4x4?? i tried 4hi, 4lo, nothing to the front wheels, i can hear it clunk into lo when i hit that, but anyways i put the old one back in and my 4x4 works...can anyone help me with this one?

the vacuum switch i have bought is identical except theres no o ring on it for some reason, but i didnt see that stopping it from working, you can only put the hoses back on one way, cus of the little stub thing, although i did try putting it on the 3 different ways and still nothing

serious pain in the ***, i can see my front differential not lasting long hope someone has a solution to this!

 

put the o ring on the new switch for the hell of it, no go..i must be getting good enough vacuum to the acuator, what if one of the other lines is cracked maybe, whats the easiest way of checking? and if one of them was leaking, should i not be getting 4x4? because it all works fine with the old switch with the ball stuck in, i just dont get it..

 

how do i check the shift fork or whatever pushes the ball in the switch in the transfer case? can i do this easily enough

 

can someone tell me if i can check the shift fork or whatever kind of apparatus it is inside my transfer case? my vacuum switch went and now with the new one it wont go into 4by, everything else works fine on it, im sure the ball isnt getting pressed in...can i even do this myself?

 

The transfer case must be removed from the vehicle, and the case must be split apart. Might want to invest in a GM component shop manual for the transfer case before attempting it yourself. While it's apart, probably be a good idea to get beefier parts, (chain, sprockets, etc).

 

i will try and do that then

 

not a huge amount of help , but you moderate it tho so