Today I went to switch my 4x4 high on and it didnt work! The light came on but it would not come on. Last weekend it worked when I switched it on in the mountains towing 4 wheelers off a snowy mountain. After the roads cleared I switched it off and the light went off. Today I went to switch it on to get up a slippery hill and it light up but would not work. I had to get out and manually lock it in and it worked fine. When I stopped I switched them outside back to auto and then then turned the switch off inside. You could hear some stuff click as the lights went off.

Whats the matter and how much will it cost to fix? Is there anything I can do? Should it be fixed immediatly? Is this a major problem?

 

Vacuum leak. Check the hoses to the front hubs.

 

are they big black hoses and where would they be located precisely?

 

this is a very comin problum with thoughs auto hubs. the best solution is to buy the waren hub conversion. you will have to get out and lock them in every time but they are alot stronger and more relieble. and eventualy the stock hubs will not lock in at all even manualy

 

Warn does not make replacement hubs for the 05 and newer Superdutys yet.


If you look on the backside of your steering knuckles you will see a rubber vacuum hose that goes from each knuckle up to the vacuum pump on the passenger side fender. Check the hoses for cracks or leaks and also check the vacuum pump to make sure it is working.

The other place you could have a leak is the rear seals for your hubs.

 

Mine didn't work yesterday when I was stuck in some snow, had to get out and switch them manually. Thats the first time my auto hubs didn't lock when they were supposed to. I have plans to change gears and do balljoints next week, so I'll do new seals in the auto hubs at the same time.

 

Where is the steering knuckle? You mean the lower ball joint?

 

steering knuckle is the big peice of metal ur tires bolt onto..

8-)

basicly its what both balljoints bolt throu..to allow ur front end to steer..

hope that makes sence.

 

well today I did an inspection of the vac system and everything around the hubs looks good. Any other suggestions?

 

I'll the second the two suggestions so far! I have had both issues actually. Had the vacuum lines go on my 2002 and 2006. The 2006 went with about 34000 on it.....per dealer the lines were "melted"..... Upon asking if they re-routed the lines so that this would not happen again, I was told they were in the right place....nice huh?

The 2002 had the rear seals go at about 14k miles. Both times replaced under warranty, and had no problems after. Put 75k on the '02 after the seal repair and had no issues.

Definitely double check the vac lines and pump, as well as the rear seals.