s4 mag impulse coupling q

[tombro44]

hi all ap's/ia's and do it yourselfers, question on bendix s4 impulse coupling. pulled assembly off my a-65 to do a heat treat flyweight and wear inspection. when i pulled the mag, noticed the nut holding the front end hardware to the tapered and woodruff keyed part of the rotor shaft was only finger tight, but properly cotter keyed. did maint referencing bendix s-20 series maint/overhaul manual. upon reassembly, book says the nut holding the bushing, drive gear, body, spring and cam, in that order, was to hold the coupling on the shaft with 180 in-lb torque. it compresses these parts together ending with the tapered female end of the cam pushing up against the tapered part of the rotor shaft and there is keyed so the cam always spins with the rotor and the body connected to the cam via the wound spring. because the body and cam/rotor turn independently periodically when the coupling is working during start (connected via spring action), i'm wondering what i'm doing wrong by following the book re the nut torque vs the way it was when i pulled it. the way i see it, a properly wound spring has to overcome the compressive friction between the body and the cam to turn independently. when i used the proper torque, the cam and body moved together after the toe of the flyweight was pushed off the stop pin by the drive lugs. there was no springing action of the cam speeding up to catch up to the drive gear. so i went back to the finger tight, and got the expected impulsing when the toe was pushed off the stop pin. it's an old publication. maybe there is supposed to be different torques for regular mag vs impulse coupled but the book didn't address it????? maybe i'm just not thinking of something or flat out not doing something right. i don't see the need for that much torque. the gear is loaded axially to the shaft, not parrallel to it. ANY THOUGHTS APPRECIATED!!!!!!!!!!!!

 

[tombro44]