Synchronizer: A cone or sleeve that slides to and fro on the transmission main shaft and makes the gears rotate at the same speed to prevent clash when the gears are about to mesh. Whenever a vehicle is rolling, the transmission main shaft is turning and the clutch gear is spinning. Even though the clutch is disengaged, the clutch gear continues to spin until friction slows it down or stops it. Thus when the driver shifts into another gear he is trying to mesh gears that may be moving at different speeds. By using synchronizers, the possibility of broken or damaged teeth is reduced and shifting effort is lowered. A transmission using synchronizers is called a synchromesh transmission.
Synthetic oil: Non-petroleum based oil.
Synthetic rubber: A man-made elastomer. The raw materials are generally derived from oily by-products. A non-elastic form of rubber. Also see natural rubber.
System: An orderly, interconnected, complex arrangement of parts. See air filtration system, air injection reaction system, anti-lock brake system, bleeding a system, brake system, bumper system, charging system, closed loop system, controlled combustion system, coolant recovery system, cooling system, diagonally split system, electrical system, electronic ignition system, engine-control system, exhaust system, flushing the cooling system, fuel system, ignition system, induction system, lubrication system, oil-combination splash and pressure system, oil-full pressure system oil-splash system, open loop system, PCV system, positive crankcase ventilation system, starting system, steering system, supplemental restraint inflatable air-bag system, suspension system, triangle-split system, and vapor recovery system |