Here's what I love about this site. Learning, and exchanges of experiences and information. I did some searching on the web, and this is a controversial subject topic. What I can determine is, it "depends on the system", and "primary" or "leading" shoe 'is' consistently the "front facing shoe". The "long or short" is where the questions come up. My Jeep Universal Form SM-1002-R6 for CJ2A, CJ3A, CJ3B, CJ5 CJ6 and DJ3A has a "Note: On some vehicles, the lining on the forward shoe is longer than the lining on the reverse shoe". Well, that clears everything up, or not. No diagrams for 4WD brakes included in manual??? So here is what I 'think' I learned. The 11" conversion pictured here has gone to a newer style "Floating Design" which indeed does use the primary short shoe up front, as the primary's "floating action" puts the most pressure on the rear shoe, the "longer shoe, by design. Now on older Willys and Studebaker too, the "fixed pivot design" aka "Simplistic" with a dual pin wheel cylinder, the pressure is said to be "equal" and the thrust of the drum to the shoe up against the pivot makes the "primary" and "longer shoe" needed up front. There is only a picture of a DJ3A rear wheel system in the SM that clearly displays that, and I found the attached pic of a Studebaker Passenger side rear brake the same as in the SM. I also found a reference that stated that "cars and light trucks used the forward long shoe design prior to 1962", but not stating "all". I could not find a picture of a Willys early model 4WD for comparison. Maybe someone has one and can share that? Now I know why I thought long shoe up front and primary. Thanks for stimulating me to learn something new today.
