Clutches

What does a clutch kit contain?

A clutch kit contains multiple parts, including the following:

• Clutch disc: The rotating part of the clutch which generates friction from plates either side of the disc.
• Pressure plate: Holds the clutch disc against the flywheel while the clutch is in use.
• Flywheel: Some clutch kits contain a flywheel, which is a thick, heavy disc that evens out the engine’s power pulses. It also facilitates rotation of the clutch disc to keep your car’s engine running. Vehicles are fitted with either a solid flywheel or Dual Mass Flywheel (DMF).
• Throw race or release bearings: Engages or disengages the clutch when the driver presses or releases the pedal.

What are the warning signs of a worn clutch?

If one or more parts of the clutch kit aren’t functioning correctly, you’ll notice a few warning signs. These include:

• Your clutch feels spongy, sticks, or vibrates when you press it
• A squeaking or a grumbling noise when you press down on the pedal
• You can rev the engine, but acceleration is poor
• You have difficulty shifting gears
• A ‘slipping’ clutch, which causes a momentary loss of acceleration

If you notice any of these issues, it’s crucial to get the clutch checked as soon as possible. Please feel free to call or book online today.

Understanding the clutch issues in more detail

• Clutch Judder: Clutch judder, also known as clutch shudder, is a noticeable vibration felt in the car when engaging the clutch, typically during take-off. It can be quite unpleasant and often indicates an issue with the clutch system.
• Clutch Slip: Clutch slip occurs when the clutch in a manual transmission vehicle fails to fully connect the engine to the wheels, causing a loss of power despite increasing engine RPMs. Imagine pressing the gas pedal, but your car hesitating or accelerating poorly due to a disconnect between the engine and wheels.
• Clutch Drag: Clutch drag, like its cousin clutch slip, affects manual transmission vehicles but in a different way. Instead of power failing to transmit, it’s the opposite: the clutch doesn’t fully disengage even when you press the pedal, causing some power to still travel from the engine to the wheels.
• Clutch Fierceness: Clutch fierceness, a less common issue compared to clutch slip or drag, happens when your car experiences a sudden and jerky movement even when you are releasing the clutch slowly and smoothly. It feels like the clutch suddenly “grabs” instead of engaging smoothly, resulting in an unpleasant jolt.

What’s involved in the replacement

• Preparation: The car is lifted onto our ramps, and the battery is disconnected for safety.
• Removal: Driveshaft, transmission, and other components are removed to access the clutch.
• Inspection: The old clutch is examined for signs of wear and damage.
• Replacement: The new clutch components are installed, ensuring proper alignment and lubrication.
• Reassembly: Everything is put back together, and adjustments are made to the clutch pedal and linkage.
• Testing: The car is test driven to ensure proper operation of the clutch and transmission.

Understanding the problem

There are several potential causes of a clutch issue, and the specific cause will depend on the symptoms you’re experiencing. Here are some common issues:

• Uneven wear: Uneven wear on the clutch disc or pressure plate can create areas with more grip, leading to sudden engagement instead of a smooth transition.
• Warped flywheel: Just like in clutch slip, a warped flywheel can cause uneven contact with the clutch disc, resulting in jerky engagement.
• Hydraulic system issues: Air bubbles or leaks in the hydraulic system can affect clutch pressure and lead to inconsistent engagement.
• Misalignment: If components like the engine, gearbox, or clutch lever are misaligned, it can cause binding and sudden release of the clutch.
• Contamination: Oil or grease contamination on the clutch disc can cause uneven friction and jerky engagement.

Dual mass flywheels

It is always recommended to change your dual mass flywheel when replacing the clutch.

On some occasions the Dual Mass flywheel can be at fault as it can wear out over time. Usually these are the rubber damping elements that naturally degrade or perish.

A dual-mass flywheel (DMF), also known as a dual-mass damper (DMD), is a rotating mechanical device used in vehicles with manual transmissions to:

1. Reduce engine vibrations: Modern engines, especially those with fewer cylinders and higher torque output, generate significant vibrations. DMFs act as a buffer, absorbing these vibrations before they reach the gearbox, protecting it from damage and improving overall drivetrain smoothness.
2. Enhance comfort and drivability: By minimizing vibrations, DMFs translate to a smoother driving experience with reduced noise, especially at idle and low speeds. Additionally, gear changes feel more refined due to the dampening effect of the DMF.
3. Enable efficient engine design: The use of DMFs allows manufacturers to design engines with fewer cylinders and lower fuel consumption while maintaining smooth operation, contributing to increased fuel economy and environmental benefits.

Here’s how a DMF works:

• It consists of two flywheels connected by a central hub with springs and dampers.
• One flywheel is attached to the engine crankshaft, while the other connects to the clutch assembly.
• The two flywheels can rotate independently, with the springs and dampers absorbing vibrations generated by the engine.
• This design effectively isolates the gearbox from the engine’s vibrations, protecting it and improving driving comfort.