HOW TO DIAGNOSE CLUTCH ISSUES

HOW TO DIAGNOISE CLUTCH ISSUES

Difficulty Changing Gears

Cause

Action Needed

The transmission was forced into position damaging the splines of the disc hub.

 

Install new clutch and carefully control the position and alignment of the transmission during installation.  Use a transmission jack and possibly install temporary guide pins to assist in aligning the transmission to the engine.

The cover assembly has been dropped.

Install new clutch.  Always inspect the drive straps for damage before installation.

The cover has not been located on the flywheel dowel pins correctly.

Install new clutch and ensure all flywheel dowel pins are in position and in good condition.  Do not use air tools to tighten the bolts.

The self-adjusting mechanism fails to lock due to worn ratchet and pawl.

Repair self-adjusting release system.  Replace ratchet and pawl.

Release bearing travel is insufficient.

Inspect release mechanism for full travel or lost motion due to worn parts.  A stamped steel release arm can wear and break.  Always remove and check arm and external pivots.  Install new fork bushings and lubricate as required with high melting point grease.

Loss of Drive

Cause

Action Needed

Transmission has been hung on the shaft during installation.  Angular misalignment of the transmission to engine.

Install new clutch and support transmission during installation.  Do not allow the transmission to hang on the clutch disc during installation.  Check for missing bell housing dowel sleeves, worn pilot bushing/bearing or foreign matter between transmission and engine including wires, cables or brackets.  The above problems will cause cracking in the segments, leading to separation of the damper and facing segments.

Driver resting foot on the clutch pedal resulting in release system sticking.

Install new clutch.  Check all components of the release system, particularly self-adjusting release systems, and guide tubes.  Check for leaking oil seals.

The clutch has been disengaged at speeds in excess of the maximum for the gear selected or the incorrect gear has been selected.  This has caused the facings to burst.

Install new clutch and educate the driver.

Noise & Vibration

Specific Circumstance

Cause

Action Needed

Noisy Clutch

Broken location lug due to worn release fork and or no lubrication

Replace any worn components and install new clutch.  Apply a liberal amount of high temp grease to the fork contact pads.

Chattering After Changing the Clutch

Flywheel surface worn

Replace or resurface flywheel and install new clutch.

Grating Noise when Pulling Away

No lubrication on the clutch fork contact areas

Clean and lubricate using the grease supplied with the Clutch Kit.

Noise when in Neutral

Oil or grease has contaminated the disc pre-damper making it ineffective

Install new clutch and sparingly use the spline grease supplied in the Clutch Kit.

Noise During Release

Worn pilot bearing or bushing

Replace pilot bearing or bushing

Noise

Installation is missing the transmission to engine dowel sleeves or pilot bushing/bearing.  This has created a concentric misalignment of the engine to the transmission.  The torsion damper is destroyed, damper springs are broken, stop pins show contact from the hub flange and the hub pilot is worn.

Carefully inspect for missing dowel sleeves and worn dowel sleeve holes in the bell housing.  Replace pilot bushing/bearing and inspect the transmission to engine alignment.

Clatter on Engagement

Excessive amount or incorrect type of grease applied to input shaft

Install new clutch and use the spline grease supplied in the Clutch Kit.

Clutch Slippage

Specific Circumstance

Cause

Action Needed

Slipping and Impossible to Change Gear

Overheating due to excessive clutch slippage

Install new clutch kit.  Check all components of the release system, particularly self-adjusting release systems and guide tubes.  Check for leaking oil seals.

Slipping and Chattering

Driver resting foot on the clutch pedal or incorrect clutch adjustment

Do not use the clutch pedal as a footrest.  Inspect for correct clutch adjustment.

Slipping

The self-adjusting mechanism has become jammed

Replace or repair the self-adjusting mechanism or in the case of semiautomatic adjusters - reset.

Slipping

Clutch facing material is oil contaminated

Replace leaking oil seals.  Clean off excess oil and install new clutch.

Clutch Pedal

 

Specific Circumstance

Cause

Action Needed

Vibration Through the Clutch Pedal

The transmission shaft has struck and bent the diaphragm spring fingers during installation

Install new clutch and carefully align and control the position of the transmission during installation.

Noise While Depressing Clutch Pedal

Seized release bearing due to excessive heat caused by incorrect bearing pre-load or loss of grease

Install new clutch and check all components and adjustments of the release system i.e. cables, linkages, fork, ball studs, fork bushings and self-adjusting release systems.

Clutch Pedal Binding

The release bearing guide tube is worn or the release arm/fork is bent or worn

Install new clutch and guide tube.  Inspect all release system components and repair or replace as needed.

Grating Noise and Stiff Pedal

Insufficient lubrication of the clutch fork, particularly at the pivot point

Clean and lubricate all components using a high temp grease.  If excessively worn, replace the fork and ball stud.

High Pedal Effort

The release bearing does not freely slide on the guide tube

Clean and lubricate the guide tube to bearing contact area with high temp grease.  If the guide tube is worn or scored, replace the guide tube.

Metallic Noise at Bottom of Pedal Travel, Difficult Shifting

The release travel is excessive causing the diaphragm spring to contact the clutch disc

Install new clutch and ensure correct clutch adjustment.

Metallic Noise at Bottom of Pedal Travel

The release travel is excessive causing the diaphragm spring to contact the bearing carrier

Install new clutch and ensure correct clutch adjustment.

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