Busted Hub?

[kdsheldon]

A little riddle for everyone:

I was out wheeling yesterday and my 79 bronco wasn't climbing worth a damn (at least relatively speaking). I had a feeling something was up with the front axle, but I was still getting more than just rear wheel drive. On the way home I braced the front wheels, one at a time, against a downed tree and gave it the gas in 4lo. When I braced the driver side wheel there was a grinding noise and no motion from the opposite front wheel. When I switched it up and braced the passenger front wheel there was no grinding and unbraced wheel spun in the sand. I double checked and the hubs were locked on both sides, and the U-joints are intact.

I thought with a open diff that if one axle/joint/hub breaks the whole axle would lose power because the torque would be routed to the broken side or the side of least resistance. My best guess is the front diff has been welded since I still have power to one front wheel. I bought the truck a few months ago and was not told the front diff was anything other than open.

Does this make sense? Any other possibilities?

[broncobuster37]

All right, call me crazy, but if the differential was welded, wouldn't both tires be forced to spin at the same speed no matter what, so if you blocked one up the other also shouldn't be able to move at all?

[kdsheldon]

With a welded diff both tires will spin at the same speed, unless something is busted.

[4x4junkie]

Jack both wheels up and start spinnin' things by hand. A busted hub should be obvious as the axleshaft won't turn with it. It could be a busted stubaxle too.

[kdsheldon]

So does the fact that the other front wheel still is under power mean the center diff is either a locker/spool/welded?

[Traveller]

If it's locked, spooled, welded, both wheels will spin, or it will die trying. If you brace the opposite wheel it'll be the other one that spins in the sand.

[kdsheldon]

Final question, if it's an open carrier and you blow out a stub/joint/lockout neither of the front wheels will have power, right?

[94stepsideford]

yeah no matter what if it was open it still should make the grinding noise as that side is the side with the least risistance

[joe_and_jeep]

Pull the diff cover. Its not a waste of time since you probably dont know when the fluid was changed last. When inside you will see what has been done to the diff. Hubs (Lockouts) are easy to remove, I dont know about yours but when I had my old hubs in they had a phillips screw so you could dissasemble the hub internals to inspect them.

No matter what was wrong all of this was good maintenance. When everything is apart relube/grease/oil everything that you pull apart. Will save lots of trouble later and help you become more familiar with your rig. If you learn in your driveway it makes it so much simpler if you have to make a trail repair cuz you'll know where everything is