Alright i can't seem to find an answer to this problem. When i get on to interstate and get up to about 70 i start getting a horrible loud winding noise. It only seems to start when im going like 70 and doesn't stop until i stop, and doesn't start til i hit like 70 again. When im going about 70 and staying a constant speed its not so loud, it generally is really loud when im speeding up or slowing down.When im going at a slower speed it sounds like a card in tire spokes.

Its not engine related it doesn't change with rpm and it doesn't change when i put it in neutral while driving. Also the noise seems to come from the passenger side tire area. I just had it in the shop and told them the problem when i was having the lower ball joints replaced on it. They are chasis and front end specialist but couldn't find a problem with it or get it to make the noise (thats my luck). they looked over bearing u joints and didn't see a problem.

I know its related to the 4wd in some way. When im going and it starts i hit 4hi and it sounded like it speeds up real quick and stops. Then i put it back in 2hi and it doesn't seem to start back up at least for a while.

My thoery - I personally think its the slider that locks the front axle shafts together. I think its trying to half engage and is grinding and when i hit 4hi and it speeds for a slpit second i think thats, just it locking all the way together. I'm gonna go pull the battery and take that cable out of the actuator and stick a vice grip on it to pull the cable out and see if it makes the noise again. I guess my question would be is does anyone else have some ideas on what this might be or is it bad to keep the front axle locked together without being in 4wd.

 

Turns out the actuator was stuck. It was only about half way out. I pulled the cable out of it and pushed the cable all the way in and taped it up real good to keep it in. Took it out on the road and haven't had a problem yet. Waiting on a new actuator now.

 

Man, this problem sounded so familiar I thought I had already responded to it. Sorry...

Hopefully the new actuator does the trick. You may want to lube up the cable while you have things apart so it will continue to work freely for quite some time.

If the new actuator does not cure the problem, you may have a leak in the vacuum line from the transfer case switch to the actuator.

 

So i didn't solve the problem. I put the new actuator in and then took it on a test drive. I first put it in 4wd worked like it was supposed to then i put it in 2wd seemed to work right. I pulled over when in 2wd truck running and in parkand climbed under my truck and tried to turn the front drive shaft and it would turn like maybe a quarter of a turn acting like it was locked in. (not supposed to do this right since im in 2wd truck running and in park)

Then the real test came got on interstate and drove about 20miles and i got my noise back man was i pissed. I pulled over pulled my cable out of my actuator and drove about 60 or 70 miles no noise.

I havn't tested my vaccum lines but i'm sure they work because i have 4wd. Now i think its the hvac or whatever it is that sends vaccum through the line to the acuator. I think whenever my truck turns on (engine running)it locks my front shaft because when i turn off the truck i can turn the front drive shaft. Theres gotta be a vavle stuck open thats always sending vaccum.

Whats this part called and wheres it located. I wanna say its on the t-case. Any idea how much it is or how hard it is to change or any other ideas?

 

Vacuum switch on the transfer case. Cheap part and fairly easy to get to. You will be reaching in around the front driveshaft up towards the top of the transfer case. It will have a vacuum connector which houses three vacuum lines. I have posted a picture quite a few times, but do not have the time right now to go back and look for it, sorry...

 

Sweet don't worry about finding the pic ill find it. This soud like it could be the problem since its always locking in when the engines running and not when its off?

Thanks again man you've helped me out so much.

 

The dealership said $41.61 for the vacuum switch. Does that sound like the right price?

I looked around for pics of it and could find a diagram picture (drawing) showing vacuum lines and such. But was wondering if you had an actual picture of it?

 

I replaced the transfer case switch and that seemed to have fixed the problem my noise is gone, and front axles lock and un-lock when there supposed to. I just went ahead and bought the switch from auto zone like $18. Heres a picture of the actuator and the transfer case switch.

The actuator was fine but i replaced it anyhow.
The transfer case switch was stuck. If you look at the picture you can see on the end with threads where theres a ball. That ball is supposed to be out, mine is jammed in causing my front axles to always be locked.

Hope this helps somebody else. sorry for the crappy pics my camera isn't to good.

[IMG]local://upfiles/10302/2441DF8B2011478BA974EC6FF3D33177.jpg[/IMG]

[IMG]local://upfiles/10302/D890B715C1B54F29BBCEA6FC3D1B8C34.jpg[/IMG]