I am doing a gear swap on a 99 1/2T 4x4, the rear wheel bearings are not like any i have seen,behind the seal is a snap ring holding a 2 piece plastic cage holding the rollers in place ( the rollers run on the axle tube) behind that is another seal. The parts man at my dealer can't find this , he spent 1 hour on Chrysler tec line, they can't identify it also. the build date match's the truck date, the rear end has not been changed,The axle tube ID is 2.24", not 2.50" like the most common. Has any one run across this, i need part numbers. thanks.