Hello,

I am trying to troubleshoot my issue with my 4x4 not engaging. I drive a 1999 Chevy Blazer LS.

My lights will light up on the push-button display, but my front wheels won't spin. Upon some research, I discovered that the actuator was a common problem with these vehicles. I went to the local auto parts store and purchased one and went through the process of replacing it.

A mechanic friend of mine helped and checked a few things before we started the process and can hear that the transfer case is engaging when buttons are pressed. We tested the old actuator and found that it was working fine (no tears, etc.). One thing that we found was that the cable would not allow any play for us to physically try to squeeze the actuator.

We figured that the cable was possibly stuck due to being frozen. I live in an area that sees some below zero temperatures commonly in the winters. I guess my first question is: Should I be able to still squeeze the actuator with the cable attached while the car is not running? I had no movement and was wondering if that was normal. I recently took it to a shop to have some brake work done and it sat in their heated shop (65 degrees) overnight. That may not have been enough to unfreeze a cable if it was indeed frozen. The cable itself looks like an easy fix (just as replacing the actuator seemed) but I want to avoid time & money if that isn't the problem.

Any thoughts!? If the cable is moved by something else, that is likely a cause, if it should have movement and not feel stuck than it may still be frozen from moisture that may have gotten in there somehow.

 

Remove the cable from the actuator, raise the right front wheel off the ground, pull the cable while manually rotating the right front wheel. The cable needs to pull out 1/2" to 3/4" and you should not be able to rotate the wheel when it locks in.

 

How do I go about pulling on that cable part? I was trying to squeeze the actuator while the cable was connected and with two hands had no luck.

Any reason(s) other than being frozen the cable could get stuck like that?

 

There is a sliding clutch sleeve, (#12) just inside the axle tube. It connects #9 & #23 together which engages the right axle with the differential. If the teeth are damaged badly enough on any of these parts, or any of the shift mechanism parts, (#15 through #22) are damaged, the axle will not engage.



Applying vacuum to the actuator under the battery should pull the cable. If not, try pushing the plunger by hand to compress the diaphram. If that doesn't work either, you'll need to do some exploratory surgery on the axle tube to find out what the problem is.