You can buy a kit to replace the internal parts of the coupler for about $10.
There's a how to here.
http://ramchargercentral.com/articles/?sa=view;article=85People say the 4x4 trucks tend to wear the coupler out pretty quick for some reason though, so many people go to a u-joint style shaft made by Borgenson for about $200.
http://www.borgeson.com/xcart/catalog/7993_Full_Size_Dodge_Truck-p-1452.html I'd like to get a Borgenson, but I rebuilt the couplers on 2 trucks so far and it helped the sloppy steering a lot.
