Silverado 4x4 help

[Fester]

So it is simpler than anything in the transfer case or switch.
There is a vacuum line that goes to each wheel hub.

The actuator is located on the firewall on the passenger side just right of the 3 PCU plug ins. Because these lines plug up with dust and condensation over time they will need to be blown out.

Each rubber hose connects to the wheel hub, just 1 on each side, pull them off the wheel hub, then find the actuator.

There will be a small inline filter, that filter will be 100% plugged with debris. Blow out with air, reassemble. There are no hose clamps or anything like that to deal with, just 1/4 or 1/8" rubber tubing.
That is about it.

Gotta love vacuum lines now a days to lock in your front wheels.

Hope that helps!

Would this still cause the service 4 wheel message? I didn't think vaccum line issue would cause the message.

 

[Catfishermen4201]

Would this still cause the service 4 wheel message? I didn't think vaccum line issue would cause the message.

Yes, 100% The vacuum actuator being plugged has an electronic plug that read up to the switch and so on....

 

[Catfishermen4201]

There is absolutely nothing wrong but dust and condensation in the vacuum lines...100% Sorry, or a broken line. The 4X4 switch goes to the actuator, the actuator gets vacuum from front differential, there is a small inline filter a few inches of the actuator on the firewall that will always get plugged and throw that code because there is the little electrical clip on it that says it is not working. Super easy to fix and no real parts to buy necessary. That vacuum line run over top of the motor of which is why after some time it will work. Just a vacuum line harness.

 

[Fester]

Yes, 100% The vacuum actuator being plugged has an electronic plug that read up to the switch and so on....

Interesting, I thought they used an electric actuator to engage the hub not vaccum..Basically engagingthe cv shaft. Learn something new every day...

 

[snow2]

Ill admit GM vehicles mpg's increased on 4x4 trucks once GM scatched mechanical warn hubs.....pretty sure ford still has Manuel front locking hubs on they're trucks over 6k lb curb weight.

 

[Catfishermen4201]

Interesting, I thought they used an electric actuator to engage the hub not vaccum..Basically engagingthe cv shaft. Learn something new every day..

No, the actuators on these years even past 2014 still have a vacuum line and harness system, sucks when you are bucking snow drifts and a piece gets ripped off...had that happen on my 2014. The switch essential controls the vacuum shuts it off or applies pressure to disengage the hub actuators.

You could try this to find out quick.
Jack up the front on both sides and leave on jack stands, block the rear.
Then while the front in the air off the ground put truck in neutral.
In 2WD turn one of the front wheels, should turn freely without the other.
Next actuate 4X4...if the same happens you will have a vacuum line issue...If not then it could be electrical but not likely...those lines and the filter coming from the main vacuum assembly on the firewall plug alot with alot of gravel road driving and mud and such...

 

[Callem'In]

So it is simpler than anything in the transfer case or switch.
There is a vacuum line that goes to each wheel hub.

The actuator is located on the firewall on the passenger side just right of the 3 PCU plug ins. Because these lines plug up with dust and condensation over time they will need to be blown out.

Each rubber hose connects to the wheel hub, just 1 on each side, pull them off the wheel hub, then find the actuator.

There will be a small inline filter, that filter will be 100% plugged with debris. Blow out with air, reassemble. There are no hose clamps or anything like that to deal with, just 1/4 or 1/8" rubber tubing.
That is about it.

Gotta love vacuum lines now a days to lock in your front wheels.

Hope that helps!

GM has not used a vacuum system on the hubs. This is for a Ford.

 

[Fester]

GM has not used a vacuum system on the hubs. This is for a Ford.

I was/am getting confused...questioning my own knowledge..happens with age I guess.

 

[snow2]

I was/am getting confused...questioning my own knowledge..happens with age I guess.

Lol yup.