ok so i have a 94 s10 blazer w/ the electronic shift 4x4. ever since i bought it the 4x4 does not engage. i have checked the vaccum acctuator, the transfer case, and all the other common things that could be wrong and nothing is wrong. everything leading up to the front differential seems to work. i am thinking it has something to do w/ in the front diff and was wondering if anyone had any thoughts on it and what i should look for.

 

When you press the button to transfer into 4wheel drive does the transfer case make aclicking sound???

 

I had problems with my 4wd going in to gear once. Turned out in the front diff there is a washer(for better lack of terms) that had been damaged. I replaced it and been good to go ever since. Not a really hard job and can be done at home if you have the tools.

 

ya it sounds like its engaging and all but doesnt engage.

and ok i'll have to take a look and see about the washer.

 

ok so i took another look at the 4wd today and double checked the vaccum actuator and vaccum lines and everything. so when i jacked it up and put it into 4hi i can see the front drive shaft spins but the front tires do not. i have concluded that it is something in the front diff or in the front axle its self. wondering if anyone can help me out on this?

i also went to the library and looked at a chiltons repair manual and found an exploded view of the front axle and front differential so heres a pic of that.

 

If you pull on the cable where it goes into the front differential, does it engage?

 

tried that and still no it does not engage

 

If you are pulling on the linkage at the passenger side of the diff carrier and nothing happens, the next step is to pull apart the front axle engagement components.

 

ok ya thats what i was thinking i was gunna have to do but is there anything that would be something common to break or look for in there?

 

This is definitely not a common problem... Typically, 4wd problems with these truck center around the transfer case encoder motor and/or the front axle vacuum actuator.

I'll see what I can dig up in regards to the front axle engagement components.