TruckandTrackWinter2018.indd

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Truck and Track Winter 2018 58
TYRES
Wheel alignment is proven to save on fuel and tyres
If the wheels on a commercial vehicle are misaligned by only a
small amount, this can have a significant impact on the handling
characteristics of a vehicle, reducing tyre life and impacting fuel
economy. Quite simply, it is just money down the drain. A half a
degree misalignment on one axle could reduce tyre life by half and
reduce fuel economy by 3-5%. See figures below.
If done properly wheel alignment should be self
financing
For commercial vehicles, savings in the region of £500 to £3000 per
annum have been reported.
Not all wheel alignment is the same
Doing the wheel alignment on a car is not
the same as doing the wheel alignment
on a commercial vehicle. The alignment
equipment is different and the method used
to set them up is different. For commercial
vehicles, be sure to go to a professional
commercial vehicle alignment company.
Tracking versus full wheel alignment
Tracking refers to the angle of one wheel
compared to the wheel on the opposite side.
For a lot of cars, resetting the tracking is all
that is needed, and that often what you get
quoted for when trying to find the cheapest
price. However, for commercial vehicles, just
re-setting the tracking is not enough. You also
have to set the wheels straight to the chassis,
straight to the steering box (or steering rack),
and straight in relation to other axles. Not all
wheel alignment systems can do this.
Fixed solid beam axles can also be
aligned
Contrary to common belief, you can align
fixed beam axles such as those on a trailer or
on a drive axle. It is not possible to adjust the
tracking, but you can still align those straight
ahead used shims or cam bolts.
Check wheel alignment at least once
a year
Some operators wait until they see major
tyre wear before getting the wheel alignment
checked. However, at this point, the damage
is already done and the money is down the
drain. And it is not just the cost of replacing
the tyres, as for every pound wasted on tyre
wear, around two to three pounds would have been wasted on
fuel. Many fleet managers now insist on a wheel alignment check
as part of the vehicles annual MOT, as well as every time a steering
or suspension component is replaced. Fleets that have adopted a
preventative wheel alignment program have claimed fuel savings
of 3-5% and improvement in tyre life of 5 – 20%.
Be wary of potholes
Every time a vehicle mounts a kerb, hits a pothole or runs along
the verge there is a chance that the wheel alignment could be
affected, and repeated knocks over time will undoubtedlymean the
alignment will need to be reset.
Recheck wheel alignment after
steering parts are changed
Every time a ball joint, track rod end, steering
or suspension component is changed, again
the wheel alignment will need to be reset.
Not all workshops do the wheel alignment
after parts have been changed.
Uneven tyre wear is not just down to
poor wheel alignment
When confronted with a tyre wear issue,
it is also necessary to investigate other
contributory factors like tyre pressures, tyre
selection, worn mechanical components
(bearings, ball joints, suspension etc). It canbe
a waste of time undertaking wheel alignment
until these other issues are put right. A
professional wheel alignment company
should be able to advise on these other issues.
Signs and symptoms of incorrect
wheel alignment
Often, the driver will be the first person
to highlight a potential wheel alignment
problem. A misaligned vehicle may require
the driver to make constant adjustments and
“fight” to keep a vehicle straight down the
road. Misaligned tyres often suffer an uneven
wear pattern and an unnecessary build up of
heat leading to premature tyre failure. The
most obvious tell-tell signs are uneven tyre
wear across the face of the tyre or excessive
shouldering on the tyres. Sometimes the tyre
wear will be on both sides, but sometimes
just on one side.
Wheel Alignment – Top 10 Tips
Glossary