The truck was locking up the front differential today, with out shifting it in to four wheel drive.. it did this a couple off times..had too back up too unlock it...once it took a long time to come out.. any ideas what might cause this.

 

by locking up you mean it shifted into 4 wheel drive without you doing it?

 

Yeah like the hubs were locking in, when i back it up the hubs would unlock. When i got home last night had too use the 4 wheel drive to get through a foot off snow or more..everything worked ok. Is there a sensor that engages the front differential when you shift it into 4 wheel drive.. I hope it's not something to do with the transfer case.

 

there is a 4x4 actuator on alot of those that i have had some trouble with through the years. they are less than 100 bucks i believe. is this the 98 in your sig?

if so, you got the push button 4x4 switch, the actuator and the transfer case itself. you could have a faulty switch that just feels like changing itself all of a sudden. when it engages 4x4, what does the light on your button do? if not the switch i would start with the actuator(aka 4wd solenoid) cheap things first

 

It's a 98..it has the shift for the 4 wheel drive on the floor, when it engages by it self the 4x4 light doesn't come on.. but when i pull the shift down too put it in 4 wheel drive the light comes on .. and where would this 4wd solenoid be located?

 

it should be under the truck

 

OK..this problem I was having kinda fixed it self, didn't have any more trouble till last week it wouldn't come out off 4 wheel drive, every morning got too drive maybe 5-10 miles before it comes out. got too keep moving the floor shift in and out off 4 wheel drive to dis- engage it. When you push the shifter ahead it stays in 4 wheel drive with the 4x4 light on.