So I got the cable, locked it in to engage.. nothing. only the rear was spinning, front was just hanging out just as if in 2 wheel drive

 

lol ok update again. Its pouring here so its making this hard to do. Anyways, I retraced the vac line from the acuator and it does go down to the transfer case. Then there is a line that comes up and meets with the t fittings by the brake booster, but ofcoarse I still have the leak there - I am trying to find where that hose goes to right now.

 

Okay,

So basically it looks like the vacuum could of been weak or shot, but when I touched that line I lost my HVAC controls so.

I am gonna just say that my vacuum lines did not have that much pressure, but should that be effecting the 4x4 - I tried to engage the diff from the actuator and clamped it once I had it about 1/2 towards the passenger side, but still nothing.

My understanding is that the vacuum as far for the 4x4 is for the actuator, correct? Even, lets say, the switch on the transfer case that handles the vacuum for the actuator line is bad, even if I manually engaged the diff, that should not be a problem...

 

If you have a vacuum leak, it can certainly affect the 4wd system. You need to get that fixed up first.

How far did you pull the cable at the actuator? Should have been pulled around a 1/2" or maybe a bit more to engage the diff. If the splines on the shaft are not lined up properly while you are pulling on the cable, it may not engage. You can change the orientation of the splines on the diff side by having someone turn the front drive shaft (transfer case in 2wd) while you pull on the cable. You should be able to feel it lock in. If you do not, then you may have a problem in the front axle.

 

I see exactly what you are saying - I am going to fix the vac leak today and then try what you mentioned. When I was pulling on the cable by myself, should I have been feeling it lock in? Or I would feel that more at the driveshaft.



UPDATE

Well, maybe you guys know better then I do, but I have a funny feeling I know whats going on.

Today I got off the highway coming to a stop and I hear a low winding noise coming up from the front. It increases and decrease on speed. Its not the motor, but I think its coming from the drivetrain.

I had this problem in my toyota, the sound anyways, when I had the front wheels locked and not in 4 wheel.

Could it be as you said, the engagement cable is not all the way engaging so the diff is intermidetly or almost engaging?

If so, then doing the fix you mentioned I think would help, or if there is damage tearing the diff apart to replace the engagement fork?

Thanks
-Jon

 

Any idea on above post?

 

You could be hearing the collar trying to engage. You can remove the cable mount on the axle and feel how the shift fork moves... If the front wheels are off the ground when you do this, you should be able to slowly rotate one wheel and engage the front diff manually from there. The cable mount is held on with 3 bolts.

 

I have the same problem with mine when I put it in 4hi or low it act like its in but my front tires will not spin for nothing. Also when sometimes when I put it try to put in 4hi or 4low both lights will flash and stay on. I called the local repair shop and he told me to put it back in 2hi and back up a couple feet and then put it back in neutral and then put it in 4hi or low and i did and still nothing i am runnin out ideas of what could be wrong. Mine is a 95 blazer s10

 

Took the truck to my buddies yesterday to throw it on the lift real quick - quick question, where the cable mount is held, once that is removed is diff fluid located in that spot?

And second question, we noticed a sensor located on the cable mount, is that directly for the 4x4 to tell the system that its engaged?


UPDATE

Alright, so I pulled everything apart. I did a vac test on the line going to the actuator, the lines are good. But oh wait, no vac while the truck is running? Go figure, and I know the actuator works. Well, I pulled the 3 lines going to the transfer case.


Let me give you a brief history-

When we initially put the truck on a lift, we found the manifold for the 3 vac lines to the transfer case unplugged. Interesting. One of the lines had a cap in it! Why? Previous owner wont say a word.

Well, my buddy pulled the cap out and plugged it back in. Nothing is working though. I just got under the truck thinking well the vac is not working so the switch is shot, let me go under to see where it is first. Pulled the manifold off, and gee look at this, two other lines have caps in them! You would not notice it until you look directly into the thing. So now I have to figure out how to get this off.

Why do you think they did this? They were having problems and instead of fixing it then just caped it so the lights would not go off?

"Oh the 4x4 worked last Winter" - previous owner


Really??? How does it work if your whole vac system to engage the front diff is unplugged?? You "imagined" it worked?

Ok, douche. This guy has been lying his *** off ever since I bought the thing, lucky I have this board and my buddy who is a GM certified to help. But crap like this pisses me off, oh well.

Rant off.

 

Mine does the same thing and I used to hear buzzing but not anymore when I hit the button. My mechanic said the motors done. The motor should make a buzz if the vaccum actuator is good. Just my two sense.