I have a 1979 FLH with a 1984 evolution engine i fitted to the frame i have a problem with the pinion shaft key after about 150 miles the pinion gear shears the T KEY and it throws the timing off ! this has happen twice since i built the engine , first thing i noticed is the the pinion shaft nut was completly loose and on the 2nd time i so called fixed it, it happened it was very loose !!now i want to add the the crank assembly is the 90-92 assembly that uses the smaller skinner pinion shaft and T key, i noticed the the t key goes into the worm drive the spacer and the pinion shaft gear ,but it doesnt seam to go into the pinion shaft gear very much at all?? so here is the question im asking (1) What is causing the nut to loosen up i used lock tight on the threads but i didnt have the right socket to torque the nut but i did do it up super tight ?? i have now ordered the correct socket ! (2) because the t key doesnt seam to go into the pinion gear very much i was thinking of machining the spacer so that the key will enter the pinion gear more , but doing this will also move the pinion shaft gear inwards but this still will allow plenty of gear surface to mesh any ideas??