Clutch Troubleshoot - chattering, rattling, slipping, stiff pedal, and more

General Auto Repair

In a car the clutch is operated by the left-most pedal using hydraulics or a cable connection from the pedal to the clutch mechanism. Even though the clutch may physically be located very close to the pedal, such remote means of actuation (or a multi-jointed linkage) are necessary to eliminate the effect of slight engine movement, engine mountings being flexible by design. With a rigid mechanical linkage, smooth engagement would be near-impossible, because engine movement inevitably occurs as the drive is "taken up." No pressure on the pedal means that the clutch plates are engaged (driving), while pressing the pedal disengages the clutch plates, allowing the driver to shift gears or coast.

A manual transmission contains cogs for selecting gears. These cogs have matching teeth, called dog teeth, which means that the rotation speeds of the two parts have a synchronizer, a device that uses frictional contact to bring the two parts to the same speed, and a locking mechanism called a blocker ring to prevent engagement of the teeth (full movement of the shift lever into gear) until the speeds are synchronized. Wikipedia:Clutch

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This is general information. This article is not intended to be specific to any unique situation or individual vehicle configuration. The purpose of this Trouble Shooting information is to provide a list of common causes to problem symptoms.

Chattering or Grabbing

• Incorrect clutch adjustment: Adjust clutch
• Oil, grease or glaze on facings: Disassemble and clean or replace
• Loose "U" joint flange
• Worn input shaft spline: Replace input shaft
• Binding pressure plate: Replace pressure plate
• Binding release lever
• Binding clutch disc hub: Replace clutch disc
• Unequal pressure plate contact: Replace worn/misaligned components
• Loose or bent clutch disc: Replace clutch disc
• Incorrect transmission alignment: Realign transmission
• Worn pressure plate, disc or flywheel: Replace damaged components
• Broken or weak pressure springs: Replace pressure plate
• Sticking clutch pedal: Lubricate clutch pedal & linkage
• Incorrect clutch disc facing: Replace clutch disc
• Engine loose in chassis: Tighten all mounting bolts

Failure to Release

• Oil or grease on clutch facings: Clean or replace clutch clutch disc
• Incorrect release lever or pedal adjustment
• Worn or broken clutch facings: Replace clutch disc
• Bent clutch disc or pressure plate: Replace damaged components
• Clutch disc hub binding on input shaft: Clean or replace clutch disc and/or input shaft
• Binding pilot bearing: Replace pilot bearing
• Sticking release bearing sleeve: Replace release bearing and/or sleeve
• Binding clutch cable
• Defective clutch master: Replace master cylinder
• Defective clutch slave: Replace slave cylinder
• Air in hydraulic system: Bleed hydraulic system

Rattling

• Weak or broken release lever spring: Replace spring and check alignment
• Damaged pressure plate: Replace pressure plate
• Broken clutch return spring: Replace return spring
• Worn splines on clutch disc or input shaft: Replace clutch disc and/or input shaft
• Worn clutch release bearing: Replace release bearing
• Dry or worn pilot bearing: Lubricate or replace pilot bearing
• Unequal release lever contact: Align or replace release lever
• Incorrect pedal free play: Adjust free play
• Warped or damaged clutch disc: Replace damaged components

Slipping

• Pressure springs worn: Release pressure plate
• Oily, greasy or worn facings: Clean or replace clutch disc
• Incorrect clutch alignment: Realign clutch assembly
• Warped clutch disc or pressure plate: Replace damaged components
• Binding release levers or clutch pedal: Lubricate and/or replace release components

Squeaking

• Worn or damaged release: Replace release bearing
• Dry or worn pilot or release bearing: Lubricate or replace assembly
• Pilot bearing turning in crankshaft: Replace pilot bearing and/or crankshaft
• Worn input shaft bearing: Replace bearing and seal
• Incorrect transmission alignment: Realign transmission
• Dry release fork between pivot: Lubricate release fork and pivot

Heavy and/or Stiff Pedal

• Sticking release bearing sleeve: Replace release bearing and/or sleeve
• Dry or binding clutch pedal hub: Lubricate and align components
• Floor mat interference with pedal: Lay mat flat in proper area
• Dry or binding ball/fork pivots: Lubricate and align components
• Faulty clutch cable: Replace clutch cable

Noisy Clutch Pedal

• Faulty interlock switch: Replace interlock switch
• Self-adjuster ratchet noise: Lubricate or replace self-adjuster
• Speed control interlock switch: Lubricate or replace interlock switch

Clutch Pedal Sticks Down

• Springs weak in pressure plate: Replace pressure plate
• Binding in clutch linkage: Lubricate and free linkage

Noisy

• Dry release bearing Lubricate: replace release bearing
• Dry or worn pilot bearing: Lubricate or replace bearing
• Worn input shaft bearing: Replace bearing

Transmission Click

• Weak springs in pressure: Replace pressure plate plate
• Release fork loose on ball stud: Replace release fork and/or ball stud
• Oil on clutch disc damper: Replace clutch disc
• Broken spring in slave cylinder: Replace slave cylinder

General Automotive Repair

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