Multi-Plate Clutch

Multi-plate clutches are clutches that consist of multiple friction and steel clutch discs that when pressure is applied, either drive or hold (brake) components of the planetary gearset. This transmission has 5 multi-plate clutches:

• Forward (1, 2, 3, 4)
• Direct (3, 5, R)
• Intermediate (2, 6)
• Overdrive (4, 5, 6)
• Low/reverse

Both the direct (3, 5, R) and the overdrive (4, 5, 6) clutches are drive clutches. The direct (3, 5, R) clutch drives the rear planetary sun gear and the overdrive (4, 5, 6) clutch drives the rear planetary carrier. The forward (1, 2, 3.4), intermediate (2, 6) and the low/reverse clutches are brake clutches. The forward (1, 2, 3, 4) clutch holds the front sun gear, the intermediate (2, 6) clutch holds the rear sun gear and the low/reverse clutch holds the rear planetary carrier.

Clutches; overdrive (4, 5, 6) and direct (3, 5, R) are balanced in terms of dynamic pressure. That is, their pistons are exposed to the transmission fluid flow on both sides to prevent pressure buildup in the clutch as speed increases. This dynamic pressure equalization process is achieved by a baffle plate and pressure-free transmission fluid supply by a lubricating passage, through which the space between the piston and baffle plate is filled with transmission fluid.

The advantages of this dynamic pressure equalization are:

• reliable clutch engagement and release in all speed ranges.
• improved shift refinement.