Chapter - 2 Clutch assembly

CLUTCH ASSEMBLY Overview

  • Presented by: Mr. Mohamed Arshad

  • Email: Automotive MohamedArshad@ncat.edu.om

Chapter II: Key Topics

  • Purpose and Operation

  • Clutch Mechanism, Components and Functions

  • Clutch Service: Removal, Components, Inspection and Procedure

  • Hydraulic System Inspection and Repair Procedure

Purpose and Operation of the Clutch Assembly

  • Function: Interrupts power flow between engine and transmission while stopping or shifting gears.

  • Components:

    • Clutch Disc

    • Flywheel

    • Clutch Cover Assembly

    • Clutch Release Bearing

    • Clutch Release Fork

Components Explanation

  • Clutch Disc:

    • Located between the flywheel and clutch cover assembly, it connects to the input shaft of the transmission.

  • Flywheel:

    • Attached to the engine crankshaft; provides a friction surface for the clutch disc and dissipates heat.

  • Clutch Cover Assembly:

    • Bolted to the flywheel; applies pressure on the clutch disc to enable power transmission.

  • Clutch Release Bearing:

    • Transfers movement from the release fork to disengage the clutch disc.

  • Clutch Release Fork:

    • Forces the clutch release bearing against the diaphragm spring of the clutch cover.

Components and Function

Flywheel

  • Similar to a brake rotor, it stores and releases energy from the crankshaft.

  • Provides friction surface and mounting for the clutch cover; helps in heat dissipation.

Clutch Disc

  • Acts as a connecting link with a friction material surface on both sides.

  • Contains a damper assembly that absorbs torsional vibrations, ensuring smooth engagement.

  • Features a wave design cushion plate to compress with the pressure plate.

  • Grooves: Present in the facing to avoid adhesion to flywheel and pressure plate.

Clutch Cover Assembly

  • Provides necessary pressure to secure the clutch disc against the flywheel.

  • Must be well-balanced to radiate heat generated during engagement.

Clutch Release Bearing

  • Conventional Type: Consists of a sealed ball bearing for smooth operation.

    • Moves with the clutch fork; reduces wear and noise.

  • Self-Centering Type: Aligns with the diaphragm spring to minimize noise due to uneven pressure.

Mechanical Clutch System

  • Components include:

    • Clutch Pedal

    • Clutch Release Lever

    • Clutch Release Cable

    • Release Fork and Bearing

  • Clutch pedal free play should be checked to prevent clutch slip due to wear.

Clutch Component Inspection

General Guidelines

  • Inspect each component during disassembly for wear or damage, including:

    • Flywheel

    • Clutch Cover Assembly

    • Clutch Disc

    • Release Bearing

Specific Checks

  • Flywheel:

    • Check for flatness and surface finish to prevent premature wear.

  • Clutch Cover:

    • Inspect for distortion, damage, and wear at diaphragm contact points.

  • Clutch Disc:

    • Measure facing thickness and check for wear in hub splines and springs.

  • Release Bearings:

    • Assess for wear and roughness; often replaced with the clutch disc and cover.

Clutch Service Procedures

Overview

  • Preventive Maintenance: Regular checks for fluid levels and pedal free play.

  • Problem Diagnosis: Identify concerns for appropriate repairs.

  • Repair: Replace worn or damaged components for effective operation.

Clutch Slippage Tests

  • Stationary Check: Assess engagement in highest gear to check for clutch slip.

  • Road Test: Observe engine rpm in relation to vehicle speed during acceleration.

Clutch Assembly Service Steps

  • Preparation: Mark alignment points for reassembly; use proper tools for parts removal.

  • Reassembly: Ensure all components are cleaned and installed correctly with appropriate torque and lubrication.

Final Checks

  1. Adjust pedal height and free play according to specifications.

  2. Ensure clutch release system operates correctly before road testing the vehicle.