Everything You Ever Wanted To Know About Rims

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Wheel Installation

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 application.

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 LUG SEAT.

3. When placing the wheel on the studs, there may be an apparent looseness 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 length 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 lengths. Less than one stud thread diameter engagement is unsafe and will cause loss of lug nut torque. IF YOU DO NOT HAVE PROPER THREAD ENGAGEMENT, DO NOT INSTALL WHEELS.

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 lengths. 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 should be used to ensure proper and safe installation.

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.

Categories: Mustang Tech

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