Im looking for any info on replacement part numbers for a 2speed axle shift actuator, specifically gaskets and the main diaphragm seal. Its off of a 1975 C-60 (2ton) chevy truck. All local parts houses and even a dealership parts counter haven't come up with anything. Im not even sure who made the axle. Ive been told it might have been Eaton but i cant be sure with the markings ive found. South Bend IND USA is stamped into the vacuum diaphragm plate. and A GM part number "3874331 GM 11" is cast into the piece that the diaphragm mounts to. Im guessing the axle is made by 1 company, the actuator bracket is a GM part and the vacuum actuator is made by a 3rd company. From the looksl of things South Bend Ind USA doesnt exsist anymore. Not good for me. Any info on these parts and axle would be appreciated, Thanks.