[john walker's workshop]

the book says 18 newtonmeters, not ftlb. that's a bit over 13ftlb. on used towers, the used shafts often walk out at that torque. 18-20 ftlb is recommended for used stuff. (not by porsche, by experienced techs). 40ftlb is asking for broken shafts (and bolts) that upon removal will gall the shaft bores. if you hear a snap, the shaft broke.