The document discusses common jobs that mechanics perform under vehicles. It describes jobs ranging from basic component replacement like exhausts and fluids, to more complex tasks like working on transmissions. Different types of transmissions, including rear-wheel drive, front-wheel drive, and 4-wheel drive models are discussed. The document also outlines dangers mechanics face while working underneath vehicles, such as falling objects, fuel ignition, overexertion, and trapped limbs. Reducing overexertion-related injuries, which account for over 20% of non-fatal incidents, is highlighted as an area for potential product improvement.

1. Common Jobs
Below is a list of the main jobs a mechanic does underneath the car. These range
from very basic jobs to more complex jobs that require substantial exertion form the
mechanic.
Component Replacement
Exhausts
http://www.gtrblog.com/wp-content/uploads/2008/07/amuse-exhaust-001.jpg
This job is best suited to having the car raised on a car lift as seen above. This
allows the mechanic a good view of the exhaust system and also enough room to
work with restriction.
Oil, Oil filter, Transmission fluid
http://howardroadgarage.com/HRG_site/images

2. Changing fluids and filters is a very common job as it needs to be done at every
service, usually ever 15,000 kilometres of a cars life. These jobs can be done
whether the car is on a life or just jacked up depending on the mechanics personal
preference.
Gearbox (high level)
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+transmission_jack_stand.jpg
This is done when the car is raised above the head. A gearbox jack is the moved into
position and lifted up under the gearbox to take the weight. The gearbox is then
unbolted form the engine block and the mechanic physically pulls the box out from
the block. The gearbox is then dropped down and the mechanic proceeds with the
task at hand.

3. Gearbox (low level)
This task is carried out in a similar manner to the previous task however the car is
closer to the ground and access is limited.
Gearbox Types and Specifications
 Weight of a gearbox(20-60kgs)
 Variations of gearboxes ( Rear wheel drive, front wheel drive, four wheel
drive)
 Jobs done on gearbox (clutch , replacing box itself)
http://www.autosavant.com/wp-content/uploads/2009/02/dsg1.jpg
4WD Gearbox
 heaviest box at around 60kgs

4.  Larger size due to more gearing
http://members.iinet.net.au/~mrdavid/tosell/6-speed%20-%20LHS.jpg
RWD Gearbox
 Middle weight at around 40kgs
 Longer than the other boxes due to it being positioned along the length of the
car
http://www.burtonpower.com/technical_1/techpics/BCgearbox.jpg
FWD Gearbox
 Lightest at around 20-30kgs
 Shortest and thinnest due to it position beside the engine block.

5. Clutch
To replace the clutch the gearbox must be removed from the car. This job entails the
use of a range of tools and the assembly of various parts.
http://www.pauls-place.com/images/Catagory/clutch-kit.jpg
Repair of components
The following is a list of commonly repaired components that require the mechanic to
gain access to the underneath of the car.
 Exhaust
 Fuel Tank
 Fuel lines
 Brake lines
 Gearbox
 Aspects of the suspension (struts)
Having the car raised allows the mechanic unparalleled access to the underneath
making the task at hand easier.
Dangers under the car
While doing the jobs listed above a mechanic faces certain dangers most of which
are catered for with existing products on the marked however there are openings in

6. the market for new products and the redesign of existing products. The list of
dangers is as follows.
 Falling objects
 Fuel igniting (welding)
 Old Oil (dermatitis and skin cancer)
 Heart Attacks (working above heart level, over exertion)
 Jack Creep (Car falling)
 Asbestos (clutch lining)
 Trapped limbs
The ratios of these dangers can be seen in the graphs below both fatal and non-
fatal.

7. The non fatal graph shows 21.6% of all non fatal injuries are cause by over exertion
this can be seen as a major issue to look into when design for this market.