Beware of scraping your car on humps

Many roads around have speed bumps (also known as humps). These are meant to control the speed at which motorists drive cars.
Despite their advantages, these speed bumps have turned out to be a problem, not to the drivers but to the cars only some of them have a low ground clearance so the parts underneath the car tend to get damaged as they get dragged over the humps.

Parts underneath the car
Some of the important parts of a car are underneath. These help ease the car’s movement and once not well maintained, could pose a threat on the driver’s life or leave the car in poor mechanical condition.
Albert Kigundu, a mechanical engineer at Total, Station Road explains that under the car are parts such as the suspension bushes, the propeller shaft, gearbox sump guard, sway bars, steering racks, the differential that connects the car axles and other parts such as the exhaust pipe, shock absorbers, ball joints and cross member which all work hand in hand to ensure easy movement of a vehicle.

Effects of speed bump collusion
“The bushes and sway bars are essential in the car’s stability and overall handling and once one of the bushes has a fault, you will easily feel it when you are drivin.”
“The most common sign of being a knocking sound underneath and instability when taking corners at a high speed,” says Eric Amadi, a mechanic.
“The ball joints also play a key role in holding the suspension arms in place and avoiding what they call in mechanical language ‘play’.”

Amadi explains that the dangers of going over bumps include dents on the gearbox sump which later on affects the gearbox. This also affects the changing of gears especially in automatic cars.
“Also driving through rough roads causes premature damage to things such as suspension bushes and ball joints and hence need constant replacement,” he adds.
Cross member is a key component as it carries all the weight of the car in front; it supports the engine and gearbox plus lateral arms behind it which support the differential and other suspension components.
Amadi notes “Though it is rare for a cross member to get damaged from a speed bump collusion, caution should be taken if a driver is passing a hump at high speed as it can cause the cross -ember to break, hence causing unsteadiness of the car when driving.”
Kigunddu says when a car experiences a speed bump collusion, the exhaust pipe is hard-pressed and keeps on narrowing and cracking every time.

This leaves little space for a car to exhale the ejected engine gas.
“The exhaust pipe will crack because of the continuous effect which in turn means the car will consume a lot of fuel, make rusty sounds and reduce on the car speed,” Kigundu says.
Other parts according to Hassan Edris Ndugga, a mechanic at Shell Jinja Road will wear out with time which will demand urgent replacement.

“When the suspension brakes bounce excessively, they get worn out and the same applies to the ball joints which will damage the wheel alignment of a car so it will tend to go off the road when you drive at speeds over 80kmph. In such a case, replacement or professional help needs to be sought urgently to avoid an accident.”
Mutebi further explains that the differential may get cracks after hump collusion on various occasions which could lead to leaking of the differential oil that enables axels movement leading to a slow movement within and of the car generally.

Control measure
Kigunddu emphasises the need for the driver to take caution when driving over a speed bump and this can only be done if when driving over a hump, the driver should drive the car diagonally.
Given that the humps are not about to be done away with on Uganda roads, Ndugga recommends car owners to invest in genuine car parts that can stand the pressure that comes with the speed bump collusion though they will still also wear out with time.

Caution

Kigundu however, cautions that changing the tyre size or tampering with tyre spacers as a way of enhancing the car height to avoid speed bump collusion should not be consideration as there is lack of uniformity when it comes to humps.
“Suspending a car should only be done if the humps are of uniform height where the car is to pass. But if not then it will not work let alone it will just bring you more problems as the center of gravity once tampered with brings about poor stability of the car making it hard to drive,” Kigunddu cautions.

But Amadi recommends that if you must increase the ground clearance of your car, you should also buy bigger tyres instead that is high profile tyres so that when they raise the car a bit it still maintains stability.

“Spacers on the other hand interfere with the geometry of the car therefore its alignment will never be the same so tampering with them should be done with precaution and as for cars with low profile tyres such as subaru legacy B4 we usually advice you to put springs than spacers.”
He adds that increasing tyre size will slug the car’s performance as it will seem unbalanced at first especially in bad weather but the driver gets used to it with time and masters how to handle the car.

TIP
The dangers of going over bumps include putting dents on the gearbox sump which later on affects the gearbox.

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