Grinding in front end/ 4WD wont work !

[smokin joe]

I went to switch it into 4WD and it made a clunk. Now it wont go into 4WD and it makes a (Grinding) noise like I am shift gears on a 4 speed when I am going down the road.
If I have it in 4 WD the grinding stops but I still dont have 4WD. It makes a clunk and wants to shift into 4WD and sometimes it does for a breif second but doesnt stay.
Any advise where to start ?
Thanks guys !

 

[DaveBen]

This sounds like you have ESOF (Electronic Shift On the Fly). I would bet you have a vacuum leak at the hubs. Does the heater controls work properly? If not, it is a vacuum leak.

Dave

 

[smokin joe]

I know the brakes dont work very good. Making lots of noise.

 

[Crumm]

I don't have any idea since mine came with manual hubs but are the auto hubs on the OBS trucks vacuum or mechanical? I didn't think the vacuum hubs came out until 99' but I don't know for sure.

 

[Big K]

Ummmm,

There is NO ESOF on the OBS trucks meaning it isn't Vacuum controlled.

 

[Crumm]

Kinda what I was thinking.

Joe, do you have manual or auto hubs? The auto hubs are very problematic on the OBS trucks and most guys end up changing them out to manual. If yours are automatic try putting them in the lock position and see if it works.

 

[smokin joe]

Kinda what I was thinking.

Joe, do you have manual or auto hubs? The auto hubs are very problematic on the OBS trucks and most guys end up changing them out to manual. If yours are automatic try putting them in the lock position and see if it works.

It has automatic hubs. I move the lever inside the cab (on the floor) and dont ever have to get out for it to go in and out of 4WD. I do have to stop to have it engage.
I put it back into 4WD and the noise stopped. HOWEVER, it clunks like it wants to kick in but wont.
HERE IS A BIGGER PROBLEM;
I jacked it up in the air and noticed the front wheel wobbles when I move it up and down like the bearing is loose or something on that order. I dont have the time to pull it apart tonight (I coach boys b-ball). It will have to wait until this weekend where I can get it inside at a freinds shop because I am sure it will take me more than a day to fix it UNLESS you guys have any time saving clues.
By the way, how can I switch it to Manual hubs ??
Thanks a heep !

 

[Crumm]

how can I switch it to Manual hubs ??

Warn Hubs

 

[smokin joe]

Warn Hubs

Thanks again People ! I found them at my local NAPA store.
Replaced them over the weekend and it is working fine now.