Manual Transmission Repair - Troubleshooting noisy gears, gears clashing, hard shifting, etc

General Auto Repair

A manual transmission is a one type of transmission used in automotive vehicles. It generally utilizes a driver-operated clutch operated by a pedal or lever, for regulating torque transfer from the engine to the transmission, and a gear-shift either operated by hand (as on a car) or by foot (as on a motorcycle). Other types of transmission in mainstream automotive use are the common automatic transmission, semi-automatic transmission, and the continuously variable transmission. Wikipedia:Manual Transmission

There are many times when the manual transmission is incorrectly blamed for shifting problems or noises that areactually caused by other reasons. Shift difficulties are frequently caused by conditions outside of the transmission or transaxle. Typical conditions
include: shift linkage, shift cables, alignment of engine to transmission, worn engine mounts
or clutch problems. Drive train noises may come from many sources such as tires, road
surfaces, wheel bearings, differentials, engine or exhaust system. Repairing or overhauling
the manual transmission will not cure these problems.

No manufacturer makes a perfectly quiet manual transmission. Gear rollover noise is present
in most constant mesh transmissions and will tend to disappear when the clutch is disengaged
or transmission is placed in gear. If clutch is properly adjusted, clutch release bearing noise
will disappear when release bearing is moved enough to slide release bearing away from
pressure plate.

Troubleshooting can be helped by driving vehicle on a smooth level road to help eliminate tire
and body noise. Note whether noise occurs on acceleration, coasting, deceleration or steady
driving conditions. Some problems may only occur when the tranny is either hot or cold.
Gear lubricant that is too thick can cause hard shifting on cold mornings before engine is
warm and vehicle has been driven.

Continue below for troubleshooting topics

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TROUBLESHOOTING TOPICS

SYMPTOM: Noisy In Forward Gears

SOLUTION: Low Gear Oil Level, Loose Bellhousing Bolts, Worn Bearings Or Gears

SYMPTOM: Clunk On Deceleration (FWD Only

SOLUTION: Loose Engine Mounts, Worn Inboard CV Joints, Worn Differential Pinion Shaft,
Oversized Side Gear Hub Counterbore in Case

SYMPTOM: Gear Clash When Shifting

SOLUTION: Forward Gears Clutch Out Of Alignment, Shift Linkage Damaged Or Out Of
Adjustment, Gears Or Synchronizers Damaged, Low Gear Oil Level

SYMPTOM: Transmission Noisy When Moving (RWD Only); Quiet In Neutral With Clutch Engaged

SOLUTION: Worn Rear Output Shaft Bearing

SYMPTOM: Gear Rattle

SOLUTION: Worn Bearings, Worn Gear Oil, Low Gear Oil, Worn Gears

SYMPTOM: Steady Ticking At Idle (Increases With RPM)

SOLUTION: Broken Tooth On A Gear

SYMPTOM: Gear Clash When Shifting

SOLUTION: Forward Gears Worn Or Broken Synchronizers, Faulty Clutch

SYMPTOM: Loud Whine In Reverse

SOLUTION: Normal Condition. Most units use spur cut gears in Reverse and are
naturally noisy.

SYMPTOM: Noise When Stepping On Clutch

SOLUTION: Faulty Release Bearing, Worn Pilot Bearing

SYMPTOM: Ticking Or Screeching As Clutch Is Engaged

SOLUTION: Faulty Release Bearing, Uneven Pressure Plate Fingers

SYMPTOM: Click Or Snap When Clutch Is Engaged

SOLUTION: Worn Clutch Fork, Worn Pivot Ball, Worn Or Broken Front Bearing Retainer

SYMPTOM: Transmission Shifts Hard

SOLUTION: Clutch Not Releasing, Incorrect Gear Oil, Shift Mechanism
Binding, Clutch Installed Backward

SYMPTOM: Will Not Shift Into One Gear, Shifts Into All Others

SOLUTION: Bent Shift Fork, Worn Detent Balls

SYMPTOM: Locked Into Gear, Cannot Shift

SOLUTION: Clutch Adjustment, Worn Detent Balls

SYMPTOM: Tranny Jumps Out Of Gear

SOLUTION: Pilot Bearing Worn, Bent Shift Fork, Worn Gear Teeth Or Face, Excessive
Gear Train End Play, Worn Synchronizers, Missing Detent Ball Spring, Shift Mechanism
Worn Or Out Of Adjustment, Engine Or Transmission Mount Bolts Loose, Transmission
Not Aligned

SYMPTOM: Shift Lever Rattle

SOLUTION: Worn Detents Or Shift Lever, Worn Shift Fork, Worn Synchronizer Sleeves

SYMPTOM: Shift Lever Hops Under Acceleration

SOLUTION: Worn Engine Or Transmission Mounts


General Auto Repair

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