Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Chevy 4x4 Actuator

My 1994 Chevy Suburban will not engage the front drive shaft. It has an electric actuator and it will not engage. the transfer case engages but not the front axal. When I shift the transfer case into 4Hi or 4Low it will shift itself but the light will not turn on. I have heared rumors that you might have to manualy connect it to the battery and have a kill switch in the cab. What is the problem and should I connect it manualy?

You will need to find out what engages your front axle. It may be a vacuum actuator or an electric actuator, not sure on your truck. I had an S-10 Blazer that did the same thing, and a vacuum line had come off for the vacuum solenoid that engaged the front axle. Looking at the axle itself should clue you in as to how it engages.

It’s very common on these truck, you need to replace the actuator. It’s super easy, and not very expensive. I would bet it’s been slow engaging the front axel for a while now, right ??? I believe the actuator us filled with a gas that gets excited when powered on, the gas leaks out over tome and bamo no 4x4. You can also buy a kit that coverts it to a cable on/off. This is cool because it gives you the option of 2wd low.

A quick google gives you links to how to videos as well as the parts.

There is a fuse if it is elc. On mine I had to ck all of them to find it as it was not the one listed for the actuator. The switch can also cause it not work.

I had this problem with the same truck four years ago and was told it was fairly common. Replaced the actuator @ $175 plus a small amount for labour and everything has been kopacetic since. There still seems to be a slight delay with the four drive panel lighting up but soon as I engage drive or reverse it comes on.

I don’t use four wheel drive more than once or twice a year (generally). This winter was an exception and I have not had to use it once. I am told that it is a good idea to periodically engage the front drive axle whether required or not. This wouldn’t mean driving in four wheel, just engaging it. Can anybody comment on the benefits of this?

I suppose that you have two actuators. One at the transfer case and one at the differential. Both need to be working for the light to come on. In addition, a position switch(s) needs to close on each to turn the light on. Have you had the truck on a lift to see if indeed it has engaged and is not a position switch problem by turning the wheels and transfer case shafts ?

Some units have easily replaceable switches and pretty much, do it yourself replaceable actuators…if you can get at them. Either way, I would have it put it on a lift to see exactly where the problem is and have all circuits to and from the actuators tested to see if it is not an electrical connection. I would do this BEFORE I started throwing actuators at it in hopes that was the problem. You can replace a switch for $25 or an actuator for $3-400 unnecessarily…Though I’m inclined to trust “london’s and gsragtop’s” opinion, get it check out at a competent transmission shop.