Originally Posted by elmo_4_vt
I always thought it was the axle that determined the Weight Carring Capacity of the truck? I guess these are the same rears that were in my Bronco, and that had a much more substantial WCC to it...
It is the weakest link of all the components that determines the maximum payload capacity or towing capacity. That could mean engine output, cooling, clutch, transmission, brakes, suspension, tires, Gross Axle Weight Rating, etc. It makes good economic sense that a design team would try to optimize all of the components so that they have similar limits.
The Level II rear axle assembly is from the one-ton South American Ranger. The only difference is that the LII's have the Torsen guts. I think that it was upgraded because of the anticipated off-road use/abuse. LII's don't have more payload capacity than most other Rangers. In fact, some other Rangers have a higher payload rating.