S10 Chevy 4x4 problems

2001 does not utilize vacuum to engage the front axel. A cable is used. There are a few conditions that can cause this. The most likely is the encoder motor. It's best to have the vehicle scanned. The TCCM is located behind the right kick panel, sometimes if it's unplugged and plugged back in, it will begin to work again.

Engage the 4x4 and using a vacuum gage check for approx. 14-15" of vacuum at the lines to the actuators.

Ok I know this question is old but for any one else who has this problem, I want to clear some info up. GM did not use vacuum on the 4x4 systems on the full size series. Only used on the S series (S10, S Blazers). Here is how to accurately trouble shoot these problems with the full size 4x4. Remove the front actuator from the front axle ( keep it plugged up and let it hang). Put the T-Case in 4x4 Hi or Lo doesn't matter. Turn key on (don't start the engine) . Now check the actuator to see if it has extended. If (no) now check the plug to see if you have current . If you have current to the plug, change the actuator. Problem solved. If no current to the plug. Check for broken wires ( fix if any) If no broken wires. There is another switch on the T-Case that sends power to the actuator Replace it.. Back to the actuator.... If everything checked out and actuator works. With the T-Case locked in 4x4, try to turn the front drive shaft by hand. With the T-Case locked in 4x4 you shouldn't be able to turn the drive shaft. If drive shaft doesnt turn the T-Case is in good shape and the problem will be in the front differential. In these cases the most common problem is an exploded thrust washer. At this point the front differential needs to be rebuilt. Back to the T-Case..... With the T-Case locked in 4x4, if the drive shaft spins, the problem will be in the T-Case and at this point the T-Case will need rebuilt......... I hope you get the information you need to troubleshoot the GM 4x4 issues.

2002 chevy s10 4 door 4x4 4 wheel drive wont engage

I HAVE A 96 S10 LT BLAZER THE SYSTEM IS THE SAME THE WAY ITS WORKS IS ON ENGINE VACUUM A CABLE FROM A VACUUM ACTUATOR LOCATED UNDER THE BATTERY TRAY RUN TO THE SHFFT HOUSING THATS BOLTED TO THE FRONT CARRIER IT PULLS ON A SHAFT TO ENGAGE 4X4 THE PROBLEM IS THE CLIP THAT HOLDS THE CABLE TO THE SHAFT **** ITS NOT MUCH MORE THEN A PAPER CLIPI TOOK OFF MY SHIFT HOUSING BENT THE CLIP SO I WOULD ALWAYS WORK SEEING CHEVY WON;T SELL JUST THE CLIP WITH OUT THE CABLE I HAVEN;T HAD A PROBLEM SENCE

Have you checked the vacuum actuator under the battery? Battery acid will leak down and cause all kinds of issues with them.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

This is all I've got.Hope this helps?

there is a vacuum actuator under the battery tray. it is the most common cause for this issue. also the cable that goes from that actuator to the differential stretches sometimes causing it to engage and not engage depending on how bad it is.

if you have any more question please ask/

By the way, if that happens again (Same thing happened to me) It was inside the front diff. That vacuum actuator that sits on the passenger side that has a vacuum hose going up to it has a built in cable that plugs into the front diff. There are little springs that go bad and there is no tension on the cable. It retracts but doesn't engage the axle.

It's 3 bolts, then pry it open just enough to get access to the spring that holds the cable together. ;) That's how I fixed my problem permanently

http://www.automotiveforums.com/t173603.html

It is called a thermostatic actuator; you can purchase one at most auto part stores or at the dealership. I have also seen a manual cable replacement kit that bypasses the thermostatic unit.