I recently bought a 91 Bronco XLT. This is my first Bronco, and first 4-wheel drive car of any kind. I was looking at the front wheels today and noticed that the front wheels have Warn Hubs. Exactly what are these? I know this sounds like a silly question, but I don't have any 4-wheel experience. My guess is that they are used to turn the 4-wheel drive on and off. "Lock" meaning that the front wheels are engaged and the 4-wheel drive system is working. "Free" meaning that the front wheels are not engaged and the systen is 2-wheel drive. Is this correct? Is this a stock item for a 91 Bronco? Now if it isn't a stock ford item, does this mean that I can't turn the 4-wheel drive system on from the console (the button for 4-wheel high and 4-wheel low)? Do I have to turn it on lock outside and then hit the button on the console? I understand that this is more reliable than the auto hubs from what I've read on this message boards so far.

Also- somewhat related, is there a procedure for turning on the 4-wheel drive system? Do I just hit the button or get out and lock the hubs, or both? Should I be in neutral or park?

Thanks everyone for your help!

 

No, the Warn hubs are not stock. The po no doubt replaced malfunctioning auto hubs. Here's the basics: the hubs (aka lockouts) physically "attach" the wheel (actually wheel bearing hub) to the axleshaft when "locked." This does not turn your 4wd on, it just makes the axleshaft spin w/the wheel. When the hubs are "free" the axleshaft sits idly while the wheel spins.

When you push the button or pull the lever in the cab for 4wd, this tells the transfer case to start spinning the front driveshaft. If your hubs are locked and you put the t-case in 4wd, you have 4wd! If the hubs are not locked, then the driveshaft still spins the front axleshafts but it doesn't do any good 'cause that power is not making it to your wheels.

To engage 4wd you should lock your hubs and then put it in 4wd. You can run w/your hubs locked at all times if you choose, or if you believe you may need 4wd for occasional patches of ice, etc. The only reason the lockouts are there is because they allow you to disconnect the wheels from the front drivetrain which in theory will provide better fuel economy. Many newer vehicles, in fact virtually all new pickups, do not have lockouts. Some have a central axle disconnects but that's another story.

 

Thanks very much for your advice and the info That's 2 or three times now that you have given me good advice.