HI people I have a major problem with my 4x4 not engaging and i read and tried every thing on here. What i do know is that my transfer case does engage and my vaccum accuator does also. So why is it that my front end does not spin. The only thing i can think of is that my cable does not get pulling in far enuff. So this being said i wonder if my cable is stuck. SO i can tell you this also right when i start my truck up and i dont have the 4x4 engagedand the vaccum actuator sucks the cable in. So if any budy knows how far my cable should go in that would be great and why also why my acuator engages even if i dont have it in 4x4. also i can tell you that the cable on the acuator only goes in about 1/2 inch. i think in needs to pulll it in a lot farther than that because if i discount it for the cable my accuator will pull back like 2 to 3 in. So i wonder if the cable is bad or if it is a internal problem in the front diff. any

 

The fact that the actuator pulls on the cable even without the 4wd being engaged sounds like a faulty vacuum switch on the transfer case. This may also explain why the actuator may not pull far enough if the switch is stuck between modes.

On your other problem, you really need to let us know what it is you are drivin' to diagnose further.

 

ok ITs a 1994 s10 blazer 4.3 cpi. well also if i try and pull the cable with my hands i can only pull it as far as the accuator does this is why i think my cable is bad.

 

When you pull it by hand, can you clamp a vise grip on it and attempt to drive it? If so, does the front axle engage?

If you can move it even a bit, you may be able to free up the cable with some penetrating oil and a bit of time just working it in and out. Or you could just replace it... But as I said, there is something amiss if the actuator pulls even when the transfercase is in 2wd mode.

 

ok so ya i'm havin similar problems w/ mine and what i've done is hooked up a vaccum gague to my actuator put it into 4wd and see if it holds the pressure. it did for me so my vaccum actuator is good. i've got mine down to it must be something in the front axle/front diff. i have another thread on here on my 4wd and in it i have a pic of an exploded view of the front axle and front diff. ur problem sounds similar to mine. so as long as ur vaccum actuator and transfer case r good and u dont have vaccum leaks ur w/ me. and i've heard from other people that the fork inside the front axle that engages the front diff is what tends to go bad if everything else works. otherwise it could be one of ur spider gears in the front diff or one of the gears connecting the front axle to the front diff.

 

Just went thru this recently with my '94 as well, when I'd start the truck actuator would pull until slack was out of the cable (at first I thought it was pulling as far as it was able but this assumption was incorrect). what I ended up doing, unmounted the vaccum actuator and set it on the wheel well (with cable and vac lines still connected so i could put the battery back in and watch what the actuator did or didn't do) start the truck hit the 4hi button, reach under driver door and turn front driveshaft if it wont turn move on to vac lines, check em all (i just replaced em all took a little time but I knew for sure i had no vac leaks when I was done) with mine it ended up being a 2 inch long piece of 3/8 vaccum line right at the actuator had a very small split on the back side of it. (btw i did notice cable was a tad jerky when actuator pulled on it so I disconnected actuator end and sprayed some pb blaster down it, reconnected cable and pushed buttons from 4hi to 2wd and back again until it worked through)so after that it worked beautifully pulled battery, remounted actuator in the proper place and 4x4 has been working great ever since. Hope you get as lucky as i did for a cheap fix.

 

The fact that the actuator pulls even when not in 4wd sounds nothing like your, 94blueknight...

Outsydr, I do believe the cable may be part of the problem, but he also has a vacuum supply problem if the actuator is pulling all of the time... In both your cases, the switch is probably leaking vacuum, pulling on the actuator a bit. This should not be the case.

 

Thanks for the help this weekend i will buy a new switch and replace the vaccum lines, plus spray some pb blaster down the cable. Does anybody know if autozone or napa supply this switch or is this a dealer only part.

 

napa has it i replaced mine and got it from napa