What is aDISC-LOCK Safety Wheel Nut?
The DISC-LOCK Safety Wheel Nut is a vibration / shock proof locking nut for hub piloted wheels that does not back off. It stays in place on the stud, thereby keeping the wheels on the vehicle.
Is wheel loosening really a problem?
Truck wheels do come loose and some wheels do separate from the vehicle. Some separations result in accidents with tragic consequences.
Even non-accident wheel loss incidents have a cost of four figures for replacement parts and a day or two of down time waiting for replacementparts. A visit to a tire shop or fleet scrap pile will reveal the fact that there is a wheel loosening problem.
Why do wheels loosen?
Wheels loosen because something is wrong, causing a loss of clamp force. This can be caused by the wearing away of paint, dirt, nicks or burrs on mounting surfaces of the wheel system, low initial torque or cocked wheels or brake drum. Easing of the clamp force leads to wheel shuffling and wear of the mounting surfaces as the truck stops and starts and encounters road shock. More wear means more shuffling and more loosening. If not stopped, this process goes on and finally the nuts vibrate off the stud.There is no question that wheel separations are also caused by broken studs. The loosening of the wheel and the unwinding of the nut are the cause of the problem.
What is clamp load?
Clamp load is the vice-like squeezing force obtained by tightening the wheel nut. EachDISC-LOCK Safety Wheel Nut and stud, when tightened to the recommended torque, holds the wheel to the hub with over 40,000# clamp force. This is about twice the clamp force of the nut and stud on the double cap nut system.
Can you forget about re-tightening withDISC-LOCK Safety Wheel Nuts?
While DISC-LOCK is in accord with other wheel end suppliers and oem in making the recommendation to re-torque wheel nuts before putting new vehicles in service, after 50 to 100 miles following a wheel/tire change or installation and at p.m. intervals, we are aware that this is not a common practice in the field.
Why should we use DISC-LOCK Safety Wheel Nuts?
The DISC-LOCK safety nut is the first successful innovation in truck/bus wheel mounting in 60 years. The DISC-LOCK safety nut improves the reliability and safety of wheel installations at the oem, tire and maintenance shops, truck stops and on emergency road service calls.
The manufacturer may hold to the principle that a customer has a responsibility to maintain and tighten wheels properly and that they will do this. However, field experience shows that this is not the case and is best considered to be a goal.
We, as manufacturers, may hold to the principle that a customer has a responsibility to be aware of and acknowledge common field practice and to provide products that are problem solvers. That is why there is a DISC-LOCK safety nut. While it can not overcome all of the problems of wheel system abuse, it is a nut that stays on studs under conditions causing the commonly used nut to run off. The DISC-LOCK safety nut is not a substitute for good wheel maintenance. The DISC-LOCK safety nut is an effective product that provides an extra margin of safety.
Can you use only one or two DISC-LOCK Safety Wheel Nuts per wheel to lock the wheel on?
No. It is important to note that DISC-LOCK recommends DISC-LOCK Safety Wheel Nut usage in complete wheel sets only (i.e., eight D L Safety Wheel Nuts on an eight hole mount and ten D L Safety Wheel Nuts on a ten-hole mount)