There is no locking mechanism. You can choose to buy a locking differential for the vehicle, they range from $500-1100.

 

Max size is 265/60/18. I have run that on both of mine. Zero rubbing. Stock suspensions. One truck was regular with ACE, the other is air suspension, no ace.

 

Is it possible the previous owner installed a tcase with a cdl lock? I can't think of any other reason why his front tires are slipping while turning. That's exactly what mine does when the cdl is locked and I'm on pavement *was just testing it out.

You might want to get under the truck and look on top of the transfer case, top right of the front drive shaft when looking towards the rear of truck, and look for this connection:



If it's there, turn it counter clockwise to disengage the cdl lock.

 

Thanks for the size snafu

 

That threaded piece?
Thanks for the detailed picture.
I'm in Freeport, nice to hear from a fellow Emerald Coaster!

 

Here are mine. Stock 255/55 on the black, 265/60 on the red. Makes a decent difference and gave a bit of a lift.

 

I was just referring to the axles both being unlocked. It is possible he has a CDL installed if someone else did it on his truck.

 

Those are 2 beautiful vehicles, especially the red w/tinted windows. I'm not sure that I've ever seen that color red on the road. Very nice.

 

We just bought the same size and X2 for the this quote.

 

It's possible the PO had installed a locker in the front. Jack up one front wheel and try to turn it by hand. If you can you don't have a locker in the front and the center diff isn't locked.
That would mean your chirping is coming from something else.
Put the front end on jack stands and turn the wheels fully right and left and check for rubbing on anything.