I have not used low range on this truck for a while, and now I am unable to get it to go into low. No problem shifting into 4x4. It just doesn't slide to the left from the 4x4 position.

Is this just a linkage that gets jammed up from lack of use? I've not crawled under there yet to look. Cold and rainy here right now...

 

lack of use seizure.
unfortunately, the only way to fix it is to remove the shift linkage, disassemble it, clean it good, and lubricate it before assembly.

and don't be surprised if the aluminum parts break during disassembly.

 

I fixed it by going under the truck and shooting PB blaster on all the moving parts. Then, I stood on the ground and was able to apply more force than when sitting in the seat. It finally budged. I worked it back and forth and applied spray on lithium grease. It seems good now.

 

the problem with doing it this way is it is very easy to break the pot metal pieces in the shifter with the extra force you get when not seated.

i have seen people snap those parts while seated, so it really does not need that much effort to do.