1. Clean and inspect all stud threads and mounting surfaces before
installation. THREADS MUT NOT BE LUBRICATED, but must be free of corrosion,
rust, burns, fractures and damaged threads. Replace studs if they are
corroded, stripped or damaged, or if any fractures are found. Always use new
lug nuts when installing new wheels.
2. Check and be certain the approved lug nuts are correct for the
LUG NUTS: It is critical that the lug nut matches the thread diameter, pitch
and seat, otherwise the installation will be improper, and may result in
damage to your wheels and could cause a dangerous condition. The three basic
types of lug nuts are: conical seat (60 degrees taper "acorn" and "bulge"),
mag or shank style, and spherical or ball seat. Thread diameter refers to
the diameter of the stud measured across the shank at the outer edges of the
threads. Thread-pitch means either the number of threads per inch or if
metric, the distance in millimeters between threads. The Seat means the area
on the wheel where the lug nut will clamp down.
Never use a conical seat lug nut/bolt on a mag or shank type lug seat and
never use a mag or shank type lug nut/bolt on a conical seat. The two are
not compatible and if installed incorrectly, the lug nuts may lose torque,
possibly resulting in wheel loss or contributing to damage or injury. In
addition, spherical or ball seat lug nuts/bolt must be used with spherical
or ball seats. ONLY USE THE TYPE OF LUG NUT/BOLT COMPATIBLE WITH THE TYPE OF
3. When placing the wheel on the studs, there may be an apparent loosenes of
fit until the lug nuts are applied.
4. Check the lug nut thread engagement. Every stud must be long enough to
thread into the lug nut a legnth at least equal to the stud diameter. For
example, a 1/2" thread diameter must thread into the lug nut at least 1/2".
Check for this problem on every stud, some may be of different lenghts. Less
than one stud thread diameter engagement is unsafe and will cause loos of
lug nut torque. IF YOU DO NOT HAVE PROPER THREAD ENGAGEMENT, DO NOT INSTALL
5. Do not allow the lug nut to bottom out on the stud or a mag shank to
bottom out on the mounting surface. This is extremely dangerous and unsafe
because the clamping force of the lug nut is not being applied to the wheel.
Check for these problems on every stud, some may be different lenghts. IF
YOU FIND A PROBLEM, DO NOT INSTALL WHEELS.
6. Lug nuts must be tightened in a star or crisscross pattern to ensure
uniform pressure and alignment. Apply torque evenly by repeating star or
crisscross pattern until desired torque is reached.
During installation, gravity causes the wheel to rest upon the highest stud.
If the wheel is clamped down off-center, it can be dangerous and damaging to
your wheels and tires over time. Do not allow the wheel to "hang" on the
studs during the initial tightening, make certain wheel is centered and
wheel supported prior to tightening the lug nuts.
7. It is recommended that you do not use air or impact wrenches to tighten
lug nuts. A calibrated torque wrench sould be used to ensure proper and safe
8. For original equipment wheels, use manufacturer specifications. For
aftermarket, if there is not a wheel manufacturer's specification in the
owner's manual, contact the vehicle manufacturer. In the event that neither
the wheel nor vehicle manufacturer give you the specifications, the
following may serve as a guideline for passenger cars and light-trucks only:
Fastener Shank Diameter = Torque Range (FT/LBS)
(12mm = 75/85)
(14mm = 85/95)
(7/16" = 70/80)
(1/2" = 75/85)
(9/16" = 105/115)
(5/8" = 125/135)
9. Make sure you check new lug nuts against the vehicle lug wrench, making
sure they are the same size.
10. If the new lug nuts/bolts have a different seat than the original
equipment, make sure you keep enough of the original lug nuts/bolts with the
spare tire/tire changing equipment so if need the spare tire can be mounted
with the correct lug nuts/bolts.
All lug nuts/bolts must be checked and retorqued to the proper specification
immediately after the first 25 miles of use. Installer must instruct the
customer to retorque or return immediately after 25 miles, so installer can
retorque. Failure to retorque is unsafe and could cause serious damage or
injury. Retorquing must be done any time the lug nuts are removed for any