Front diff stuck engaged on 95 chevy k1500 z71

SOURCE: fuel gauge k1500 98 Z71 fuel gauge vibraiting or bouncing

gauge failing (dash)

SOURCE: 1996 chevy K1500 transfer case slipping out of 4 wheel drive

Your trouble is most likely not in the transfer case but in the front differential engagement solenoid.

SOURCE: front diff does not engage on my 95 chevy k1500

first make sure the new actuator is gettin' power. Do this by placing your hand on it while someone engages the 4-wheel drive. Then try cleaning your vacuum actuator valve and vaccuum lines leading up to it for possible holes.

SOURCE: I have a 1990 K1500 4X4 Chevy pickup that wont

I had the same problem on my 90 K1500, it was the 4 wheel drive actuator unit itself. Bout it at the local parts store for 30 bucks and installed it in 10 minutes or less - and vavoom! 4 X 4 back in business.

Harvey N Tawatao

• 3854 Answers
• Posted on Dec 02, 2009

SOURCE: I drove my 1994 z71 truck through a creek and now 4x4 doesn't wrk

On the full size, the front actuator is electric, not vacuum.

When in 4wd mode, a switch on top of the transfer case conducts 12 volts out to the actuator. Wire #50 (brown) is the 12v feed, and it conducts to the light blue wire (#900) to the actuator.
When shifted out of 4wd, the switch opens up and no voltage goes to the actuator.

Check voltage at the connector for the front actuator (at the front differential - it looks like a large bullet that threads into the front diff.) If it has 12 volts, the actuator is the problem. If it does not have 12 volts, check the transfer case switch and the power feed to the transfer case.

I'll assume it is the actuator, if the plug to the actuator is getting 12 volts when in 4wd.
The way this actuator works, is it is a sealed chamber that gets heated by voltage. When it heats, the pin in the end swells and pushes a shift fork in the front differential. The shift fork engages a spline on the passenger side of the differential, and boom! you have 4WD.

GM offered an upgrade to this actuator that is a motor instead of a heated device. However, it requires a small harness addition, a spacer, and a new actuator. It is about a $150 to $200 option.

If I were you, I would buy a new heated actuator. They are available at most auto parts stores, and are about $90. They are also on eBay for about $55 plus shipping. These are very easy to change - just thread out the old one, and thread in a new one.

Good luck, That actuator is usually the problem 90% of time.