General information 5-speed manual transmission

Due to the energy released during combustion in the cylinders of the air-fuel mixture, the engine crankshaft develops torque, while its rotation frequency lies within a fairly narrow range. Most modern OHV engines develop their maximum torque at about 2500 rpm. With an increase in engine speed to 4500 rpm, the magnitude of its torque decreases, so that a further increase in power is no longer possible. Engines with an overhead camshaft (OHC) are able to develop significantly more torque, but in a much narrower speed range.

The use of such a component as a gearbox in the transmission line allows you to adjust the relationship between engine speed and the speed of rotation of the driving wheels of the car, ensuring a sufficiently high return of the power unit in almost any operating conditions of the car.

Smooth transmission of torque from the crankshaft to the input shaft of the manual gearbox (RKPP) provides the clutch assembly, the design and principle of operation of which are discussed in the Chapter Suspension and steering this guide. Sequential gear shifting in the process of changing the speed of the vehicle is provided through the use of a multi-stage gearbox in the gearbox. The gear ratios of each of the five stages of the manual transmission provide maximum efficiency in transferring the power developed by the engine to the driving wheels of the vehicle. On non-front-wheel-drive models, the gears on the gearbox's input shaft transfer the engine's torque to the gears on the output shaft, which is usually located just below and away from the input shaft. The gears of both shafts of all stages of the forward gears of the manual transmission are in constant engagement, however, they continue to rotate freely on the bearings until the clutch and the corresponding synchronizers actuate. When switching from one gear to another in the process of movement, some gears are sequentially released and others are blocked on the shaft. Blocking and releasing of gears is carried out due to the operation of clutches rotating between them and the shaft and equipped with stoppers. In modern gearboxes, synchronization of the shift stages of all forward gears is ensured. The friction elements of the synchronizers ensure the smooth introduction of the corresponding gears into engagement with the shaft with a preliminary alignment of the revolutions of the toothed locking clutches.

Due to the complexity of the design of the manual transmission, the lack of free sale of the necessary interchangeable internal components and the need to use special equipment, the compilers of this Guide do not recommend car owners to independently overhaul the gearbox. Repairing a box in a car service workshop is a rather expensive operation, which means that alternative options for replacing a failed unit with a new one or a refurbished one should be considered. Any useful information on the repair and replacement of the transmission can be obtained from Mitsubishi service stations. Regardless of the chosen troubleshooting method (repair or replacement), independent dismantling of the box from the car will significantly reduce material costs.

In view of what has been said in this Part of the Chapter, the reader’s attention is only offered a description of the process of performing such procedures that lie within the qualifications of an average amateur mechanic, such as general adjustment of the gear shift drive and removal / installation of the manual transmission assembly.