95 K2500 won't engage 4WD

[studeclunker]

I did a search first, honest I did! Thought I had asked this question here before.

Anyway, we have a '95 K2500 with tons of mileage on it. It won't shift into 4WD anymore. I can put it in and it appears to be in, but won't engage the front axle. What is going on?

Truck: 1995 K2500 (gas) 350 automatic.
problem: won't engage front axle in 4WD.

Any ideas????

[dieseldawg142]

most likely your axle actuator, or the 4wd indicator switch on the transfer case,
i just replaced both to go wit my newly rebuilt t-case.

[studeclunker]

Originally Posted by dieseldawg142

most likely your axle actuator, or the 4wd indicator switch on the transfer case,
i just replaced both to go wit my newly rebuilt t-case.

Thank you both! What do the Actuator and indicator switch look like? On the left side, I can see a small circuit board where everything plugs into the tranny. Is that what you're talking about? Or do I need to look under the right side too?

Looked on the 'Tube and found a video! Very cool. Well looks to be easy enough to do. It's just a matter of getting under the truck. Looks simple enough that even an ignoramus like me can do it!

https://www.youtube.com/watch?v=dv6pUKKOAqI

[b454rat]

x2 on the actuator.....

[pjmoreland]

4WD quit engaging on my '89 K1500 recently. Replacing the actuator solved the problem for me. I got part number 2FWDA1 from O'Reilly. It screws into the top center of the front axle housing. It took about 10 minutes to replace it.

https://www.oreillyauto.com/detail/c...or/mpi0/2fwda1

[DeadheadNM]

Does this K2500 use an electric switch to engage the front axle? Just curious as my 99 K2500 makes use of a manual shifter for the transfer case.

[57taskforce]

Pete, the 98-99 trucks use a servo style electric actuator that is quite a bit more reliable than the earlier thermal actuators.

[dieseldawg142]

Originally Posted by 57taskforce

Pete, the 98-99 trucks use a servo style electric actuator that is quite a bit more reliable than the earlier thermal actuators.

yup, more reliable and much faster. my new to me '97 has the electric actuator and as fast as i can pull the 4by lever, front axle is locked in.
does not matter if your t-case is electric shift or manual shift, the actuator just engages your front axle. my kid's '96 has the thermal one and after seeing how fast it engages he now wants to upgrade to the electric one.
i think the reason the thermals are not so good is because it has to stay "on" whenever your in 4by whereas the electric is off and on- not always on which prob prolongs the life of them

[DeadheadNM]

Thanks guys. I get some brief gear grinding when engaging 4wd, but it engages

[dieseldawg142]

Originally Posted by DeadheadNM

Thanks guys. I get some brief gear grinding when engaging 4wd, but it engages

i know gm says "shift on the fly" but i still do like i do with my square, put it in neutral and shift. if nothings spinning, they will glide into 4 wheel