Gear Noise

^ Gear whine. Gear whine may be present during normal driving in first, second, third and fifth gears. Gear whine will not be experienced in fourth gear because the input shaft and output shafts are rotating at the same speed (1:1 ratio) resulting in no gear loading multiplication.

Possible causes: Lack of lubrication, gear tooth contact pattern. The contact pattern should be centered on the tooth and have a width of approximately 75% of the tooth. Tooth contact pattern which is too low, too high or localized on the front or back of the tooth may be contributing to gear noise.

NOTE: DURING THE GEAR MANUFACTURING SMALL IMPERFECTIONS SUCH AS PITS, NICKS, BURRS OR CHIPS ARE REMOVED BY A GRINDER. THE SMALL GRINDING MARKS LEFT BY THIS PROCESS ARE LOCALIZED AND SHOULD NOT BE CONSIDERED AS A SOURCE OF GEAR NOISE.

^ Gear clicking, knocking. Noise may be present in any gear.

Possible cause: Chipped or broken tooth.

^ Neutral rattle. Neutral rattle occurs with the engine running, transmission in neutral and clutch pedal released. The rattle will be much louder if the vehicle is along side a wall or in a garage. Neutral rattle should be evaluated in an open area with windows closed and all accessories turned off. Some light neutral rattle is normal and will be present in all transmissions.

Possible causes: Low lubricant level, misaligned clutch housing, clutch disc runout, Clutch spline lubrication, clutch release bearing.

^ Gear rattle. Gear rattle occurs during acceleration while upshifting through the gears (first through fifth). The rattle may occur in more than one gear. Some light gear rattle is acceptable. Lugging the engine will magnify gear rattle.

Possible causes: Low lubricant level, misaligned clutch housing, worn gear(s).

^ Driveline clunk. Driveline clunk occurs with abrupt throttle tip-in, tip-out. Some driveline clunk will always be experienced due to the accumulative backlash in the driveline system.

Possible causes: U-joints, engine/transmission mounts, axle ring and pinion backlash, propeller shaft angles.