Misalignment Effects

Misalignment Effects

Alignment Precautions

The following alignment precautions should be observed:

1. The vehicle should have come to rest from a forward movement. This ensures, as far as possible, that the road wheels are in natural running positions.
2. It is preferable for alignment to be checked with the vehicle laden (Refer to ‘Specifications’, page 4-1-2).

Road Wheel and Tyre Balance

Static Balance

For smooth riding, precise steering and the avoidance of high speed ‘tramp’ or ‘road wheel hop’, all tyres are balance checked to predetermined limits. To ensure the best degree of tyre balance, the covers are marked with yellow spots on the outer sidewall and these indicate the lightest balance point of the cover.

The original degree of balance is not necessarily maintained. It can be affected by uneven tread wear, tyre removal or refitting, by road wheel damage or eccentricity. The vehicle may also become sensitive to imbalance due to normal wear of moving parts. If roughness or high speed steering troubles develop and mechanical investigation fails to disclose a possible cause, road wheel and tyre balance should be suspected.

Warning
If balancing equipment is used to dynamically balance road wheels, always jack both rear road wheels off the ground when rear road wheel balancing, otherwise damage may be caused to differential. This is doubly important in case of vehicles installed with a limited slip differential, as in addition to possible damage to the differential, the vehicle may drive itself off the jack or stand.

Dynamic Balance

Static imbalance can be measured when the tyre and road wheel assembly is stationary. There is another form known as dynamic imbalance which can be detected only when the assembly is revolving.

There may be no heavy spot, i.e. there is no natural tendency for the tyre and road wheel assembly to rotate about its centre due to gravity, but the weight may be unevenly distributed each side of the tyre centre line. Laterally, the eccentric road wheels give the same effect. During rotation, the offset weight distribution sets up a situation which tends to steer the road wheel to the right and left alternately.

Dynamic imbalance of the tyre and road wheel assemblies can be measured on suitable tyre balancing equipment, and corrections implemented. Where it is clear that a damaged road wheel is the primary cause of severe imbalance, it is advisable for the road wheel to be renewed.

Road Wheel Nut Torque Tightening

Order - Tighten every second nut until all five nuts are tightened.

Tighten all road wheel nuts in two stages.

1. To 80 Nm (60 lb. / ft) in one continuous movement.
2. To 135 Nm (100 lb. / ft.) in one continuous movement.

Inform the customer that the wheel nuts are to be torque checked after 32 km (20 mile).