I did some digging around and noticed a couple post about "4WD On the Fly".
I have my hubs locked position. When I test drove the truck in warm weather 4x4 worked fine, my test was to turn the stirring sharp and check for the jirking feel.

Now the temp is below zero -10 to -20 and all of a sudden no 4x4, cannot spin front tires.

Front drive shaft is spinning when I engage. So, I am thinking vacuum problem. I did the vacuum test and sure enough the defrost come on when I change to 4x4.

Is there a temporary fix, that will get me by. I am planning on replacing the hus with warn manual hubs. I read something about plugging the vacuum hoses that go to the hubs, how does that help the hubs to engage?

Thanks

 

plug the lines by the vac pump..turn the hubs to lock when you want 4x4

 

Are your hubs in locked or auto position? If they are in auto now, what Ron said will work, If they are already in lock the you have some other issues.

 

They are in locked position now.

 

they are now ?? where they locked when you tried 4x4?? and did you swtich the switch to 4x4 when you locked them??

when you lock the hubs..you still have 2H and 4x4 with the switch..just the hubs will always stay locked till you turn them back to auto..

 

I keep them in locked pos. all the time.

 

sounds like the hubs will need to be taken apart and cleaned up...

 

Try working them back and forth. Maybe do it with wheel of the ground to spin tires while working so you can tell if the lock. Look a Guzzles site for hub work http://guzzle.rbmicro.com/. The vacuum system don't matter when you have your hubs locked.

 

unless he wants heat out the vents while he is in 4x4

 

Ok, you got me there, but he wasn't complianing about his vents.

 

lol good point.. but keeping the toes warm is a big thing for me to..

 

Yeah, I know what you mean and that is a good point. I don't think vacuum is his biggest problem. If his hubs are locked and driveshave turning when engaged, he has hub issues and on both sides. I'm wondering if they are indeed turned to the locked position. I know that mine were worn enough that I couldn't tell locked from auto.

 

I will recheck things and let all of you know what I find.

Thanks

 

If your hubs are locked in they will turn the driveshaft. The problem might be in the transfer case shift solenoid. If you or someone just looked at the front driveshaft while the truck was moving.

Jack up the front of the truck and see what goes on. If you can spin one of the wheels and the driveshaft turns, you know where the problem lies. If your transfer case was shifting properly you'd be hearing something bad up front. I can't imagine the hubs have totally failed when manually locked in.

Keep us posted on your findings,

Austin

 

I came back and read my previous post, and it sounds a little harsh. It's not intended to be.

I just wasn't sure how the you verified the front axle is turning. I would be check the the fuses and relays for the transfer case too. On my '01 the fuse is in the battery junction box under the hood behind the air filter box. It is a 30A maxi fuse (#17) and attatched to the side of that box is a smaller one that contains the relay for the tranf. case actuator.

Good luck. Having 4WD is no doubt a must this time of year.

Austin