4x4 high not engaging - need advice

I'd bet your 4 low doesn't work either, you're just getting the

2.72:1 reduction to the rear axle. to test the actuator, pull it from the axle, take a foot long dowel and push the plunger in... it make take a little bit of rocking of the truck to get the splines to line up. if it goes in easily and the 4X4 lights up (the ign has to be on), the actuator is bad. if it doesn't light up, stick a VOM into the actuator plug and check for 12V also check the blubls in the floor console, if it doesn't go in or goes in super hard... you've got internal axle troubles. hth, Bret

You think 4x4 low is working because the gear-reduction is, the front axle is likely still not engaging. I'd look at the actuator, get GM's updated part...

I'll test the actuator as you mention. The bulb is good, already checked. I can always tell when 4x4 is engaged by turning while in

4x4 on a dry road, you can feel the front pull and tire drag; however, I will retest the 4x4 low on a dirt road to verify. Thanks for advice.

//Hunter

I'll be checking this weekend. And if needed, will get the updated part.

Thanks again.

//Hunter

Put the truck on four very secure jack stands. You'll be able to tell if the

4 wheel drive is working by the wheel rotation. As well the differential will lock with the key on and the solenoid engaged.

Brian

This doesn't really work for the new stuff Brian. I have a friend who had a late 90's burb and it would spin all 4 on the rack. Then he (before I could say anything) tried to stop the front DS with a pair of channel lock pliers, to no avail (dumb ass). However putting the rear wheels on the emissions roller and the front wheels against chucks, it couldn't roll out. In the snow, it had 1 wheel drive. Just something to think about - it had push button 4wd.

-- "Ignorance is preferable to error; and he is less remote from the truth who believes nothing, then he who believes what is a wrong." - Thomas Jefferson Formerly: KJ the Lonely Grease Monkey

It is the actuator. Thanks for all the advice.

//Hunter

Follow-up: Thanks for the advice. It was the actuator. Replace it today and all works fine. I purchased the actuator on ebay from payless parts. The guy said it is made in America (was important for me). I only paid $36 + $5 shipping, excellent deal as the dealer part is over $100 and at the parts shop it is $80 even checked dealer cost and that is $85 and $65 respectively. If it does not hold up for several years I will let the group know.

//Hunter