The tire pressure must be correct.
The tread pattern must not have one-sided wear, and its depth must be at least 4 mm.
The tire must not have any damage such as cuts, punctures, foreign objects, etc.
Wheel suspension, steering, tie rods, including shock absorbers, must be in perfect condition.
Test drive before balancing
If a car arrives at an authorized station with a complaint about «roughness», be sure to perform a test drive before balancing.
In this case, the master must familiarize himself with the nature of the malfunction.
In motion, you should set at what speed the imbalance appears.
Raise the vehicle on a lift immediately after the test drive.
Mark the installation location on each tire.
Remove the wheels and balance the wheels.
Balancing on a stationary balancing stand
Clamp the wheel on the balancer.
NOTE: It must be remembered that when balancing wheels, as with any other repair, cleanliness is the most important rule. Only by following the cleanliness, you can achieve an impeccable result. Dirt and rust in the area of contact and the centering hole of the wheel distort the result.
Before placing the wheel on the wheel balancer, clean the bearing surface, center hole and disc.
Install the wheel with tire on the balancer.
NOTE: To tighten the wheel, use e.g. self-released collet adapter for balancers K4S 5271 (pic. 4.13).
It guarantees 100% wheel alignment and gentle disc clamping.
Conical centering adapters do not provide 100% wheel alignment on the bench.
With a deviation from the center of 0.1 mm, an imbalance of 10 grams appears on the wheel and tire.
Procedure for wheel/tire balancing
Spin the wheel with the tire on the balancer.
Check the running of the marking strips on the sidewalls of the tire in the area of the bead.
Check the tread pattern with the wheel spinning.
NOTE: Wear on one side, wear patches due to locked-wheel braking, or severe uneven wear will not achieve a smooth ride by balancing. In this case, the tire must be replaced.
Check the accuracy of rotation of the wheel with the tire. If the wheel with the tire does not rotate smoothly, although there is no flattening of the tire, radial and lateral runout may be the cause.
Check the tire rim for radial and lateral runout.
If radial and lateral runout are within tolerance, balance wheel with tire.
NOTE: Do not use more than 60 grams of weight per wheel. If more weights are needed, good balance can be achieved by minimizing if necessary.
Minimization
The display of the balancer should show 0 grams.
As an alternative to minimization, you can use the balancer VAS 6230.
Screw the wheel to the hub.
First tighten the lowest wheel bolt to approx. 30 Nm.
Then tighten the remaining bolts also to 30 Nm in a diagonal pattern. Due to this, the wheel is centered on the hub.
Lower the car onto its wheels.
Now tighten the wheel bolts crosswise with a torque wrench to the prescribed torque.
After balancing the wheels, take a test drive.
If you still feel a wobble during a test drive, then it may be due to a balancing error due to the centering of the wheel.
Wheel and hub centering errors can overlap each other in unfavorable cases. For this reason, beating is also possible. It can be eliminated with a finishing balancer
Balancing test stand VAS 6230
With the balancing test stand VAS 6230, in addition to the well-known static balancing, additional functions can be performed (pic. 4.14).
A feature of this system is to check the radial force of the wheel with the tire during rotation.
During this test, a roller presses on the wheel with a force of approximately 635 kg. Thus, the force acting on the bearing surface of the wheel from the road surface during movement is simulated.
Due to the radial and lateral runout in the wheel and tire and the different stiffness in the tire, the forces acting on the contact area of the tire with the road change.
The VAS 6230 recognizes and stores the position of the maximum measured radial force in the tyre. This measures the position of the shortest distance between the rim flange and the center of the rim.
Visitor comments