When I meet Baker Kalema at CKK Garage in Wandegeya, a Kampala suburb, he is watching closely as the gearbox of his manual Toyota Corolla is being opened. His car was towed to the garage and he was informed that his clutch had burnt, due to among other reasons, poor clutch release and balancing. The solution was to fit a new clutch and gearbox seals. Kalema’s gearbox was also running on low cubic centimetre oil.
According to Peter Amadi of Dalas Auto Limited in Bunga, Kampala, driving habits that damage your vehicle are distributed into manual and automatic transmission vehicles.
Poor or wrong gear selection
First, when you start a parked manual car, its speed ought to increase gradually from zero to, say, 140km/h and so does its gears from gear one to five or higher.
However, if you start the car and skip gear one and go straight into gear two simply because you want to drive fast, the car engine fails to leave up to the command and will struggle to move.
Wrong or poor gear selection is also manifested by the speed at which you drive vis-à-vis the gear being selected.
The sound of the engine will help you determine the right gear to use.
“If the engine is producing a grinding sound, it means you are engaging a wrong gear for a wrong driving speed,” Amadi advises.
Wrong speed for wrong gears
The gearbox works in a way that when you increase your driving speed, the gear within which you are driving also increases.
This is because different gears have different strengths. Gear one, two and three are heavy gears while four and five are light.
This explains why when you engage gears four and five immediately after starting the car, the car will not pick speed.
It can, for example stay in the 100km mark, making you think that your speedometer is defunct.
It is also important to note that the speed of the car increases gradually, not from zero to, say 100km/h in a second.
Poor clutch use
The main aim of the clutch in any manual car is to engage and disengage motion. However, what will damage your gearbox is when you drive with the clutch pedal half way in the gearbox.
“Instead of releasing the clutch fully for the car to go, some motorists push the clutch pedal in the gearbox halfway.
This means you are using the clutch pedal to reduce the speed of the car and this causes the clutch to burn. When it burns, it means you cannot engage any gear.
The more you drive, the more the asbestos material of the clutch peels off and this will in the long run affect the performance of the gearbox,” Amadi explains.
If you also do not check the level of cubic centimetre (CC) oil, the gears will start making noise and it will eventually lead to gearbox tear.
Alvin Nkini, a mechanic in Gaaba, observes that in cars that come fitted with the sport drive system: “Before you change from driving mode to sport drive, you need to slow down and increase the speed gradually using sport drive. When you turn on sport drive in high speed, you will blow your gearbox.”
Automatic transmission fluid levels
When you do not make it a habit to check your automatic transmission fluid (ATF) levels, they will lead to gearbox failure as you drive.
This is because ATF plays an important role of keeping the gear transmission system well lubricated.
However, you must be careful not to use any ATF you come across, but rather the one prescribed on the dipstick. Some dipsticks are engraved with use “CVT only.” CVT means continuously variable transmission, a different type of ATF.
Recommended service procedure
Like most car parts, it is also advisable to service your gearbox after covering every 50,000km. This involves changing the ATF and cubic centimetre oil. When you are changing engine oil, change every other oil in the car.
When you drive for more than 50,000km, the oils and fluids become dirty. The dirt will start restricting movement of the fluids and this means that you will not get the right gears or even none at the right time.
Cost of replacing a gearbox
On average, a new manual gearbox costs between Shs20m to Shs28m for cars with modern technology. With automatic cars, there are gearboxes that cost as high as Shs40m depending on the technology inside the gearbox.
However, the cost of second hand manual gearboxes ranges between Shs1.5m to Shs3m depending on where you get it.
Second hand automatic gearboxes cost between Shs800,000 to Shs1m for common cars such as Toyota Premio, Spacio, Toyota Corolla, among others. For other brands such as Audi, Subaru, used gearboxes cost approximately Shs850,000.