When a wheel is installed incorrectly it can cause disc thickness variation in the rotors. As a result, the vehicle starts to experience pulses when braking. In contrast, when wheels are tightened correctly, the vehicle should maintain its proper condition. In order to prevent reoccurring pulsation complaints, this article will show you the correct procedure for installing and tightening wheels.
Installing a Wheel
The process of installing a wheel is very simple and only involves two key steps. When both steps are done properly whell induced runout will be elinated as a potential problem. For example, the steps are listed below:
1. First, tighten the wheel using the correct sequence. (More on that below)
2. Second, use a process called “step torquing”.
Wheel Tightening Procedures
By tightening the wheels lugs in the correct fashion promotes both safety and proper brake operation. In order to preform the installation correctly, all wheels should be tightened and torqued in the same process:
1. Hand tighten all lug nuts using a star pattern.
2. Next, tighten all lug nuts to approximately 1/2 specification using the same star pattern.
3. Tighten all lug nuts to full specification using the star pattern.
Note: If the wheel is not a 5 lug nut wheel, then use the proper tightening pattern listed in the image below.
Note: When working on alloy or aluminum wheels we strongly advise re-torquing the wheels after a short test drive.
Note: Never use lubricants or penetrating fluids on wheel studs, nuts or moving surfaces. Likewise, wheel nuts, studs and mounting surfaces should be clean and dry. If penetrating fluid is used to remove the wheel lugs, clean the studs and nuts before reinstalling. If desired, a thin layer of moly-lube may be used on the inner mating surface of the rotor where it meets the hub to slow down corrosion.
Calibrating Your Impact Wrench
WARNING: Wear safety goggles when using torque sockets
Torque socket are calibrated to an impact of 250 lb.ft. with 90-100 psi of air inlet pressure. Because most impact wrenches vary from 100 lb.ft. to 600 lb.ft. with various air inlet pressures, it is necessary to perform a simple calibration in order to ensure that torque accuracy will be uniform with each respective socket. The steps below will go over how to calibrate the impact wrench:
1. First, tighten a wheel nut whith a torque socket. (For example, try 100 lbft. socket)
2. Second, test the torque setting of the wheel nut with a calibrated torque wrench (Preferably a dial indicator), by measuring the break away torque in the tightening direction.
3. If the torque of this wheel nut is more than 100 lb.ft., turn the impact wrench output down.
4. Repeat the above procedure until the wheel nut, torqued socket, and torque wrench are in sync. – Plus or minut 5 ft.lb of the 100 ft.lb. torque socket. As a result, the impact wrench is now calibrated for any of the torque sockets.
5. Each time the torque sockets are used, remember to set the impact wrench to the proper setting.
As long as the air inlet pressure is not changed, this setting will always be accurate for the torque sockets.
TIP: Failure to properly torque the wheels can take an otherwise perfect brake job and cause it to comeback with a reoccurring pulsation complaint.
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