I bought this 2002 F-350 years ago, I only use it for plowing my 800' driveway. Last year I got stuck in some heavy snow, I noticed my drivers side front tire wasn't spinning but passenger side was, I had both hubs locked in. The guy who had the truck before me put Warn locking hubs on, maybe the hubs are getting a little old. I plan on putting new locking hubs on this year, I notice there are 2 kinds of locking hubs, auto and manual, I don't know which ones I have on my truck, is there anyway I can tell? Does it matter which kind I put on?

 

Welcome to the site.

Generally the hubs will either say Lock-Free or Lock-Auto on the hub face.
You might try disassembling the hub and cleaning and re lubing it prior to replacement.

 

My hubs say lock/free. I did some checking online to see what locking hubs the truck came with originally, it said that a 2002 F-350 Heavy Duty came with Auto locking hubs. I guess the hubs I have in there now are manual locking, I have a dial on the dashboard that I can set to 2 wheel, 4x4 high, and 4x4 low, does that mean it had auto locking hub from the factory?

 

Can I just put back in manual hubs without doing any changes to the vacuum lines?