The Posi*Lock nut assembly uses a simple, yet effective locking technique. A slot allows the nut to compress and bind the threads. The aluminum material tends to "grab" the steel inner sleeve when under pressure. Tightened correctly, this nut is especially free from vibration induced loosening.
Tighten the nut to 15-20 lbs-ft if your carrier is using a ball bearing housing (stock or aftermarket double row ball bearing). If you are using a Timken tapered roller bearing housing, you will need to set the endplay to about .015"-.017" (the axle will move in and out of the carrier this amount). Consult your carrier manufacturer's recommendation on endplay.
To lock the Posi*Lock, apply a thread lock compound to the allen screw, and then tighten to 17 lbs-ft, thereby compressing the threads.
NOTE; THIS IS NOT A WARRANTY ITEM, SO PLEASE PAY ATTENTION. You may need to install a spacer or take similar action to ensure that the threaded sleeve is engaged at least 1/2" to 3/4" in the nut. This is seldom necessary. However, variations from machine to machine do sometimes necessitate some additional fitment procedures.