front axle auto lock hubs
This is actually fairly common to the push button 4WD axles.
As I recall, My wife and I had the work done at a local truck garage for about $350, but a good shop manual, tools, and a garage to do it in would be much cheaper. Ours had the universal joints replaced at the same time since the axle was apart, and they aren't that expensive. Kind of like the throw out bearing when you replace the clutch plate. A cheap no-brainer that can prevent future tear downs.
Good luck!
Joe
I had the same problem during the summer. Whenever i backed out of the driveway and turned sharply the hubs would click and start to engage. I took the hubs apart thinking that they needed to be greased. It turned out that the guy at the brake shop put one of the hubs back together wrong. One of the washers was on the wrong side of the bearings or something along those lines. If you started noticing this shortly after having your brakes worked on it might be something that simple. After putting the hub back together correctly and adding a little grease the problem went away. Even though it was just one side that was wrong, it seemed to affect both hubs because the drive shaft would start to turn. If you have a manual or know how they are supposed to go you can check them yourself in very easily.
Chris




