Those indicators are common on many fleet maintained medium duty and up vehicles here (Ontario, Canada).
Got popular after the province rubber stamped pretty hefty weight increases on trucks, then acted surprised 18-24 months later when wheels started flying off trucks. :confused2:
Less common here is a retainer ring, that is sized for the specific diameter of the bolt pattern. Mainly what that is intended to do is if you have one nut loose, it is hopefully prevented from vibrating off the stud totally. Not a bad idea, esp. if it prevents a 1/4 lb nut from bouncing through my windshield !
Rgds, D.
Got popular after the province rubber stamped pretty hefty weight increases on trucks, then acted surprised 18-24 months later when wheels started flying off trucks. :confused2:
Less common here is a retainer ring, that is sized for the specific diameter of the bolt pattern. Mainly what that is intended to do is if you have one nut loose, it is hopefully prevented from vibrating off the stud totally. Not a bad idea, esp. if it prevents a 1/4 lb nut from bouncing through my windshield !
Rgds, D.