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Gearbox

Gearbox

The automatic transmission has 4 planetary gears with accompanying clutches, brakes, and freewheel. It has two shafts (primary and secondary shafts). Two of the 4 planetary gears, P1 and P2, are located on the primary shaft.

The P3 and P4 planetary gears are located on the secondary shaft.

The power from the primary shaft is transmitted to the secondary shaft via two intermediate gears. From the secondary shaft the power is then transmitted to the final drive via two final drive pinions, one driving and one driven.

The transmission has 5 forward gears and one reverse.

A certain amount of slipping normally occurs in the torque converter. The amount of slip is proportional to the torque amplification which it produces. In order to reduce fuel consumption a Lock-up clutch is used in the 3rd, 4th, and 5th gears (on the V6 petrol only in the 4th and 5th gears). This clutch is located in the torque converter and when it is engaged there is a direct drive through the torque converter.

In order to effectively use the engine torque a certain amount of slipping is allowed in the Lock-up clutch. This function has the purpose of saving fuel and operates in the manner that when the torque demand is moderate (small throttle opening), the Lock-up clutch slips within a certain speed range (50 - 200 rpm). This means that a change down to a lower gear is avoided.