Manual gearbox

Noisy in neutral with engine running

• Input shaft bearings worn (noise apparent with clutch pedal released, but not when depressed).*
• Clutch release bearing worn (noise apparent with clutch pedal depressed, possibly less when released).

Noisy in one particular gear

• Worn, damaged or chipped gear teeth .*

Difficulty engaging gears

• Clutch fault.
• Worn or damaged gear linkage.
• Incorrectly-adjusted gear linkage.
• Worn synchroniser units.*

Jumps out of gear

• Worn or damaged gear linkage.
• Incorrectly-adjusted gear linkage .
• Worn synchroniser units .*
• Worn selector forks .*

Vibration

• Lack of oil .
• Worn bearings .*

Lubricant leaks

• Leaking differential output oil seal .
• Leaking housing joint .*
• Leaking input shaft oil seal .*

*Although the corrective action necessary to remedy the symptoms described is beyond the scope of the home mechanic, the above information should be helpful in isolating the cause of the condition, so that the owner can communicate clearly with a professional mechanic.