you have to tighten nut to crush spacer between brgs to give specific rolling resistance on pinion the nut has locking ring incorperated to stop it coming loose 32mm,since your brgs will already be well run in tighten nut till you can feel spacer and freeplay has gone and tighten a little more in incraments to give nlight resistance while rocking diff flange,but becareful not to go to far