Well I've done some work here and there on my blazer.

I finally pulled the battery tray out. Found the actuator bellow was completely blown out.

Also the vacuum lines are all jacked up, so I'm still tracing it down... But the vacuum line to the actuator was going full time. Got it plugged up for now. I've already checked to make sure my front drive shaft turns and engages.

Now here's where it gets interesting. The other day, my GF and I were driving around the destroyed Six Flags outside of New Orleans. I popped the hood, (I have access to the cable and vacuum line still) pulled the cable and locked it in with some vice grips. Well went about 30 feet and had a loud heavy clunk from the front. Stopped and checked everything out, nothing appeared to be broken. Well I did a few 4Lo launches in some dense gravel. I don't think the front tires pulled at all. Hard to tell.


Now I guess I'm looking for suggestions on what to do from here. I'd rather not worry about the actuator get up. As, pulling that battery is not fun.... So is there a somewhat easy way around this? On the cheap side as money is going into other aspects of this truck.




I pretty sure my rear diff locks in fine still. I like tearing sheet up when I can and I see two tire marks every time.

 

the older s10s actually put that actuator on the fender so it was really easy to get at it when the vacuum failed, maybe the vise grips werent holding the wire all the way out and it popped out.

also usually when there is solid vacuum going to the actuator under the battery that means the vacuum switch is stuck wide open. i know people have made cable kits, basically a pull cable you can put inside the cab to engage the front axle, i even ran a little vacuum switch under the hood going to it on a truck i used to have to bypass that switch, you just have to pop your hood everytime you want to engage 4x4.

best way i have found is rip the entire front end out of these trucks and throw them in the garbage and put a dana 44 up front with manual locking hubs, they just work

 

If did alot of off roading I'd look more into doing a swap. The pull cable idea might be the way to go. The vacuum switch that's supposed to be on the fire wall is missing lol. Few things on the truck were jerry rigged by the previous owner.

 

the actuator needs a constant pull while driving to engage completely. It is like a sleeve with teeth on it the engages to a shaft with the same teeth on it. Chances are at a stop if you pull the cable and clamp it with a vice grip you are just holding the sleeve up to the shaft and not actually over the shaft. That is when it's vacuum actuated, it pulls on it while moving and slips into place and then it tugs the rest of the way.

The vacuum lines at the transfer case are probably swapped or the vacuum switch is messed up casueing constant vacuum to the actuator. Replace all old crusty vacuum lines and make sure they are in the right places. With some searching a diagram can be found.

My biggest problem with the system is why they put the thing UNDER the battery tray, could it not have been somewhere accesible or at least not under something that can leak acid????

 

I honestly think the vacuum switch is gone. I can't even find the plug for it lol. I'm pretty tech savvy, just never had much wrench time with this kind of 4wd setup. My other trucks were old IDI ford's with manual hubs. A 86 F250 with 38s, long wheelbase ext cab. My other was a 93 reg cab with a 5spd. Yea, the whole battery tray thing is ridiculous. I thought about sleeve thing when it happened but I spaced out I guess lol. I'll probably rig up some kind of pull cable. I guess that's the next step after I put load bags on the rear.