Dana 60 Hubs possibly not enagaging???????

[Texas Limo]

I have a 97 F350 with Auto hubs. I went up to the snow and the 4x4 didnt work. The front drive line spins but the wheels dont. I believe the hubs are'nt engaging. Ive done some research and what Ive found is that these Hubs work off of vacuum. I dont understand how thats poisiinble when there are no vacuum lines runing down to the front axel. Can anyone please explain? I have the same axel and hubs on my rock crawler and the Hubs engage fine on it and there is no vacuum line running to my front axel on it either. Any input would be greatly appreciated.

[1997stroke]

I know on the SD trucks that there is a vacuum line that hooks into the knuckle. Not sure if the OBS are the same setup or not.

[jdffafarmer]

I pulled the auto hubs off our 93 F250...put manual lock outs on...got a pair of Warns from the junk yard for $20...ours worked fine but wouldn't disengage sometimes and there is a bearing retainer that was getting bent up inside them that would tie them up...we did bend it back in place and worked when we took them off...your problem may be that same retainer but keeping them from engaging? the hubs are pretty simple if ya start to pop them apart...i could pry get some picks of our auto hubs on the shelf if ya need to see what they should look like

[jdffafarmer]

and the OBS trucks do not have the vacuum hubs...they are engaged by the turning of the shafts

[ryandamo]

take the cover off the hubs and see if any water or dirt got in there, some times they sieze up when this happens, there is no vaccum they are activated by cenrifugal force when the axle turns. It is a very common problem and the only fix is to turn to manual hubs.

[crazy_canadian]

Also, if you take them appart, clean them real good with brake cleaner or something and blow compressed air into them to get the dirt out.
And DONT put grease on it. First time I cleaned mines I put grease on it, and then next week I found myself stuck in a 4 foot snowbank on 2wd, hubs were frozen shut.
My truck has manual hubs, but I do clean them before every winter. Dirt and grease do get inside.