What is a Wheel Separation?
What do two teenagers in Oklahoma and a woman in Georgia have in common? They were killed after being struck by runaway wheels that separated from vehicles. A wheel separation or wheel-off happens when a wheel detaches from a moving car or tractor trailer and becomes a runaway wheel and a deadly projectile.
In the case of the Oklahoma teens, they were killed instantly when a tractor trailer wheel separated and bounced across an interstate median and crashed through their windshield. The Georgia mother was killed when a wheel flew off a SUV and struck her in the back while she was walking along a sidewalk. The SUV had just been serviced at a tire store less than a mile away. Serious injuries can also occur to the occupants of a vehicle that suddenly loses a wheel such as in a roll-over collision.
How Often Do Wheel Separations Happen?
Wheel separations happen frequently and can lead to serious injuries or death. In 1992, the National Transportation Safety Board conducted a special investigation into wheel separations on tractor trailers due to a rash of seven fatalities during a three week period. The NTSB estimated the incidence of wheel separations to be about 750 to 1050 per year on tractor trailers. However, these figures are grossly underestimated as wheel separations not causing damage or injury often go unreported and the study also did not include passenger vehicles.
Why Do Wheels Come off Cars and Trucks?
The most common cause of wheel separations is due to undertorquing or overtorquing the lug nuts on a wheel after a wheel has been re-installed during some type of mechanical service that requires the wheel to be removed, such as a tire installation or rotation. All commercial and passenger wheels must be tightened or clamped to the wheel assembly with specific torque values depending on the type of wheel and vehicle. The specific values can be found in the vehicle owner’s manual. Generally, passenger vehicle wheel nut torque values range from 60 to 120 foot pounds.
It is critically important for all lug nuts to be tightened onto the studs using proper wrenches that are capable of measuring torque values such as a torque stick (2nd photo black stick) or some other type of calibrated torque wrench (1st photo). If too little torque is applied, the nuts on the left side of the vehicle will gradually unthread themselves and fall off. The nuts on the right side of the vehicle will generally fracture and break off due to excessive force being applied to the stud which causes the studs to bend up and down every time the tire rotates. Similarly, too much torque stretches the lug studs which weakens the stud and will cause it to fracture or break.
Some examples of a mechanic negligently installing a wheel may include failing to determine the specific torque value for the wheel and vehicle, using an air gun without a torque stick or wrench and guessing how much torque has been applied, or using a torque wrench that is out of calibration. Any of these failures could lead to almost immediate catastrophic consequences as wheel separations usually occur within a short period of time, generally between 100 and 3000 miles, after the wheel has been negligently re-installed by a service provider. Most vehicle and wheel manufacturers recommend that lug nuts be checked and re-torqued within 500 miles of driving after a wheel installation in case the lug nuts have loosened.
Another cause of wheel separations occurs when a mechanic fails to clean the wheel surface from all dirt and rust prior to re-installing the wheel. A mechanic must clean any rust, dirt and other contaminants off of the wheel surface with a wire brush before re-installing it. If not, the contaminants prevent the wheel from properly clamping to the wheel assembly. Over time, this lack of clamping force can cause excessive force on the wheel studs and ultimately cause the stud to fracture or break off and the wheel to separate.
Contact us if you or a loved one have been seriously injured or killed due to a wheel separation or wheel-off. It is very likely that a tire service provider or tractor trailer company failed to follow proper maintenance or installation procedures and may be to blame for the wheel separation. Our attorneys, including Bill Parker in our office, have significant experience and knowledge in wheel separation cases and can provide you a free consultation to review the details of your case to help you get the compensation you deserve. We take on wheel separation cases all over the United States with the assistance of local counsel.