Another Center diff lock question

[Thunder90]

hey all,
Trying to diagnose inop CDL
Here's the scenario:

• 153k. Lube / service history suspect.
• No CDL lights - switch and dash. Suspect bulbs.
• Depressed dash CDL Switch causes familiar click under dash AND I can hear actuator under truck whir.
• No locking occurs
• Dealer Masrer tech suggests tearing into xfer case to determine if mechanical. $$$!

I've read threads that suggest driving in figure 8, fwd and reverse, and that has not helped.
How should I proceed?
How important is this to fix? DD duties. Light offroad.

Thanks in advance.

 

[Julian Stead]

Be 100% that there is fault, be sure it isn't locking first. Fix the bulb or jack a wheel up and try spinning the driveshafts by hand to check that the diff lock isn't engaging, lift a front wheel if you got a rear LSD.

 

[NC-Grayson]

Center Diff Light Fix - My Experience