4 X4 Donest Work Help?

[2000chevysilv]

I gota 1999 z71 with 172,000.

 

The auto 4 wheel drive works, but when u push 4wl or 4wh it doesnt work, i got stuck on purpose and only auto 4 worked, BUTTTT just now i put my truck on 4 jack stands and all 4 spin on high and low.

 

 

WTF??

 

 

what could be the issue??

[Wires]

I gota 1999 z71 with 172,000.

 

The auto 4 wheel drive works, but when u push 4wl or 4wh it doesnt work, i got stuck on purpose and only auto 4 worked, BUTTTT just now i put my truck on 4 jack stands and all 4 spin on high and low.

 

 

WTF??

 

 

what could be the issue??

 

Could be a bad solder connection on the dash push button switch.

[c4cruiser]

Usually when something inside the dash switch assembly goes, you will see a Service 4WD message and you cannot engage any 4WD selection. The switch indicator light turning off is a good visual key too. The typical fix for the switch is to replace it. Costs about $60 and takes 5 minutes to swap it out.

 

Do a search on "Service 4WD" or similar terms and you should get some information on this type of problem. It's possible that something inside the transfer case is going bad. Do you know if the fluid has been changed recently? With 172K it may be a good idea to change the fluid in the transfer case and both diffs.