Page 23 - Commercial Vehicle Engineer - September 2021
P. 23

 Richard Tawlks
“If wheels are badly misaligned, what essentially happens is that their tyres are pushed down the road at angle. This results in what’s known as feathering, whereby the edges wear down quicker than the rest of the tyre.
“If it’s only a minor misalignment, the tyre’s life could be shortened by 10 to 20%. If the wheels are badly misaligned though, the edges of the tyre could very well wear down up to 60% quicker than they should. So, from a cost point of view, the danger
of wheel misalignment is ultimately that you wear through and therefore need to replace your tyres a great deal sooner than you should.”
Given that truck tyres can cost hundreds of pounds, this can be a significant
cost. Another cost that results from
wheel misalignment is increased fuel consumption, adds Malc England from Haweka. “A one-degree misalignment on one axle could increase fuel consumption by about 5%,” he says. “It also means that there is increased production of carbon dioxide and other harmful emissions and increased stress on mechanical components.”
England adds that there are various causes of wheel misalignment, apart from potholes, such as replacing a steering joint - there are no guarantees that the replacement restores the vehicle geometry to within the vehicle manufacturer’s tolerance. “In addition, the vehicle may have made contact with a kerb, or might regularly run off-road or over uneven ground.”
But wheel misalignment is something that is easy to miss as it doesn’t necessarily make an appreciable difference to how the vehicle feels to drive.
Wheel alignment tests are quick to complete
“Depending on how extreme a particular case is, wheel misalignment can cause real trouble for a vehicle’s tyres”
      “It is not always that the problem is being ignored by a driver, but it is about who is analysing the vehicle data to identify if the running costs are outside of the expected parameters,” adds England. “If the vehicle is part of a large fleet, a driver will have many key performance metrics to focus on and tyre life and fuel efficiency may not be at the top of their agenda. It will be the fleet manager that may be the first to observe that a particular vehicle is using more fuel than expected or the average tyre life is significantly different to other vehicles in the fleet. But all of these symptoms are lag measures, which come to light when there is a problem.”
Regular alignment
With such costs that can be incurred, it is important for transport operators to check their vehicles’ wheel alignment regularly, says England.
There are many wheel alignment solutions on the market, and some now use laser technology to measure the vehicle geometry, such as those from Tecalemit Garage Equipment Ltd, sold by Haweka. “More sophisticated models accommodate the wireless transfer of data to a PC to enable the workshop technician to produce reports of the vehicle configuration,”
adds England.

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