Just turned 100.,000 miles, when it's gets down to 20-30 degree F range the 4X4 shift lever won't budge from 2WD to 4WD. After it runs for awhile it will usually engage but not always. When it doesn't, I need to put a space heater underneath the truck and let it warm up, that usually does the trick. Problem is...in the winter if I need to plow to get it in the garage, it's stuck in 2WD which is hard to plow in. Any ideas what problem I'm dealing with?
Thanks in advance.