A gearbox is a mechanical way to transfer energy from one device to another. It is an essential ingredient of car. It has a system of metal gears that enmesh with each other and directly increase torque and reduce or increase speed in a motorcar. Generally these work with a special gear oil, which cuts down the friction between the metal gears for a longer life. Modern boxes last many years, but depending on the type of driving they may last longer or wear out. All have a clutch which is a plate which is synchronised with the gears to facilitate easy shifting of gears.
This plate or clutch can either be operated manually or automatically. In automatic cars the gear changes are synchronized with the speed of the car and change automatically. But a special slot is a requirement for a reverse gear or an uphill climb.
When to Change a Gear Box
Gear boxes last a life time, but depending upon the type of driving they may require repairs. In case one wears out or its gears break, the only option is to either change the item or repair it. Changing a box is a costly proposition; as such it’s always better to get it repaired. In both cases the box will have to be first removed. It can be fitted back after it is repaired. Gear boxes are mostly at the bottom of the car where they are located. Mostly they will be at the rear of the engine. To remove one is not easy and one will have to bend down under the car to remove a gear box.
Tools Required for Change of a Gear Box
Before starting to remove a gear box, it is imperative that the proper set of tools is available. These tools should be so placed that the person removing the gear box has easy access to them. It is preferable to keep them on an oil cloth close to the car within easy reach. The following tools will be required; a hammer, Torx set, sets of spanners, Socket set, Chisel to ping hub nut loose, Pliers and a girl friend to serve you tea.
Steps to Change a Gear Box
The first step is to drain the oil. This can be done by getting under the car and loosening the drain plug of the gear box. This is at the bottom of the car. A metal trough should be placed under the drain plug to collect the gear oil; otherwise the entire oil will spill and spoil the floor.
The next step is to remove the front wheels. This is essential so that the mechanic can have free and unfettered access to the box.
The third step is to try and down the gear box. This is done by unloosening the drive shaft hub nuts. These will require some effort and it is important that the correct size wrench be used. Follow up by removing the wishbone pinch bolt. By using a hammer the wishbone next to the ball joints is removed.
The gear box is normally kept synchronized with the engine with a set of bolts in a housing. These blots will now have to be loosened and removed. Once the drive shaft is disconnected, the mechanic would have finished almost 60% of the job. Ensure that you have a jack for the engine; otherwise it may fall to the floor.
Follow up by removing all linkages and pull the box away from the engine. The task is now complete and the box can be sent for repairs, which is a specialized task.
Fixing the box is a greater pain than removing it. It will have to be held firmly, to position it in the housing and immediately the bolts must be tightened. Once it is in position the other linkages can be re-connected.
Generally removing a gear box of a small car is about an hour’s job. But removing it from larger cars is best left to a professional.