The clutch is a crucial part of the drivetrain of any automobile equipped with a manual transmission. It has two main functions: the first is to connect and transmit power from the engine to the transmission; and the second is to allow the engine and transmission to be disconnected from one another. This lets the engine remain running without turning the wheels — allowing the vehicle to remain running while at a stop.
The entire clutch assembly contains a few parts that all work together to achieve these goals. These include:
- The flywheel, which is a contact surface for the friction disc, bolts to the engine.
- The friction disc provides the pressure to hold the engine to the transmission.
- The pressure plate provides the other contact surface for the disc as well as holds pressure on the disc.
- The throwout bearing, which moves back and forth to press in the springs of the pressure plate.
- The clutch linkage and hydraulics which transfer power from the pedal to the throwout bearing
- The clutch pedal, which acts as the primary input for the driver to the clutch.
What Does it Cost to Repair a Clutch?
Depending on the type of repair that must be made to the clutch and the kind of vehicle it is in, the clutch replacement cost can vary. Due to where the clutch is located in the vehicle, oftentimes clutch repairs require the removal of the transmission from the vehicle to gain access to its components.
Most often, a clutch repair will require what is called a clutch kit, which includes a clutch friction disc, pressure plate, throwout bearing, and a pilot bearing.
Let’s look at a few examples of clutch repairs to get an idea of the cost of replacing a clutch (using an average UK shop rate of £70/hr).
1. A 2010 Honda Civic 2.0L does not move with the clutch engaged. The technician has diagnosed a worn clutch and will need to install a new clutch kit in the vehicle. The flywheel is able to be resurfaced at a local machine shop for £35.
- Clutch kit – approx. £145
- Flywheel machining – £35
- Removal and replacement – 6.3 hrs at £70/hr, £440
- Diagnosis – 1.0hr at £70/hr, £70
- Shop supplies – £8
- Total cost of repair – £698 + GST
2. A 2013 Subaru WRX premium 2.5L has a rear main oil seal leak, which has caused the clutch to slip and overheat. The technician inspected the flywheel and found that it was damaged and would need to be replaced.
- Clutch kit – approx £320
- Flywheel – approx. £90
- Rear main seal – approx. £35
- Removal and replacement – 9.0 hrs at £70/hr, £630
- Diagnosis – 1.0 hr at £70/hr, £70
- Shop supplies – £8
- Total cost of repair – £1,153 + GST
3. A 2004 Dodge Ram 3500 5.9L has a soft clutch pedal and a hard time shifting gears. The technician has diagnosed a failing clutch master cylinder and needs to replace the hydraulic assembly.
- Clutch hydraulic assembly – approx. £105.
- Brake fluid – £4
- Remove and replace – 1.7 hrs at £70/hr, £120
- Diagnosis – 1 hr at £70/hr, £70
- Bleed the clutch – 0.3 hrs at £70/hr, £20
- Shop supplies – £8
- Total cost of repair – £325 + GST
4. A 2001 VW Golf 2.0L has trouble shifting gears and a long clutch pedal travel before disengaging the clutch. The technician inspects the clutch control linkage and notices the cable is starting to stretch and must be adjusted.
- Clutch cable adjustment – 0.7 hrs at £70/hr, £50
- Diagnosis – 1.0 hr at £70/hr, £70
- Shop supplies – £8
- Total cost of repair – £128 + GST
As you can see, depending on the make and model of the vehicle, a clutch repair can vary in price – with most clutch repairs do not require removal of the transmission. This normally costs in the area of £90 to £445. Repairs requiring the removal of the transmission cost between £625 and £1,785 on average.
How Does the Clutch Engage and Release?
When the driver presses down on the clutch pedal and releases the clutch, the pedal acts on either a hydraulic system or a mechanical linkage. If it is hydraulic, the master cylinder pushes fluid through the clutch lines and into the slave cylinder.
This moves the throwout bearing into contact with the springs on the pressure plate, which releases the tension on the friction disc. If it is a mechanical linkage, a series of pushrods or cables will move the throwout bearing instead.
The disc is now able to spin freely without grabbing on the contact surfaces of the flywheel and pressure plate – meaning that the transmission and the engine can now spin independently of each other. We need this independent movement when switching gears with the transmission or when at a stop to keep the engine running.
When the driver releases the clutch pedal, the throwout bearing moves back out of contact with the pressure plate springs and the spring tension is put back on the friction disc. This forces the engine and transmission to spin together and allows the engine to drive the transmission, which moves the car.
What are the Symptoms of a Bad Clutch?
Because the clutch involves both mechanical and hydraulic components, there are a couple of different symptoms that can arise and various clutch prices and other costs involved in repairing them. Common symptoms of a clutch in need of repair are:
Anything in a vehicle that is moving can cause noise, and there are a few common areas in the clutch that have associated noises. The most common noise associated with the clutch is a squealing noise when it is disengaged, which can be a sign of either a failed throwout bearing or a bad pilot bearing in the flywheel.
Both can be replaced individually without replacing the entire clutch. However, both also require transmission removal and come with a clutch kit.
The other noise that is sometimes heard is a clunk when engaging the clutch, which is normally due to a broken spring in the friction disc or a bent pressure plate spring. These are both also associated with a harsh engagement of the clutch and, sometimes, a vibration in the clutch pedal when engaging.
- Vehicle is unable to move
The most common issue requiring clutch repair is a vehicle that is unable to move or that revs up without going faster when accelerating. This is called clutch slipping and is due to either a clutch friction disc that is worn out or a friction disc or flywheel that has been overheated and can no longer be grabbed onto by the clutch disc.
This can also be caused by oil contamination on the clutch disc from a leaking engine or transmission seal. All of these problems require replacement of the clutch disc and pressure plate, and either replacement or resurfacing of the flywheel.
- Vehicle stalls or is hard to shift between gears
If the clutch is unable to be disengaged, the engine and transmission will be unable to rotate at different speeds. This means that the driver won’t be able to change gears or, in some cases, even start the vehicle, or that the vehicle will stall when coming to a stop because the transmission slows the engine down too much.
The most likely cause of these symptoms is a failure in the connection between the clutch pedal and the throwout bearing. This can be caused by air getting into the hydraulic system, a failed master or slave cylinder, a leak in the hydraulic system, or a clutch that is misadjusted.
The repairs vary in this case. It could be as simple as readjusting the clutch linkage or bleeding the clutch hydraulics, or it could be as complicated as removing the transmission to repair or replace damaged lines or cylinders.
Sometimes the clutch hydraulics can share the same fluid as the brake hydraulics – meaning, that a brake fluid leak or severely worn out brake pads can affect the operation of the clutch.
- A burning smell when the clutch is applied
If the clutch disc is worn out, the clutch is applied too slowly. If the engine RPM is too high when shifting gears, the friction disc can slip against the surfaces of the pressure plate and flywheel, causing the surfaces to overheat and the disc to start to burn.
If the disc is overheated for too long or too frequently, it can cause a clutch failure, leading to the disc slipping all the time and causing movement issues.
If there is no permanent damage, the driver will just have to learn to apply the clutch more properly to keep it from becoming overheated further. But if the clutch starts showing other symptoms, then it will need to be replaced.
What Can You Do to Prevent Clutch Repairs?
A clutch is a normal wear item in a vehicle and will need to be replaced in the lifetime of that vehicle; normally between 60,000 and 120,000 miles. However, there are steps that you can take to prevent premature clutch failure.
The biggest cause of premature clutch failure in vehicles is the improper operation of the clutch — either by a new driver who is learning how to drive or someone who is not used to driving manual transmissions. The most common problems occur when the driver revs the engine too high when taking off from a stop, shifting gears, or letting the clutch apply too slowly.
If you smell something burning when applying the clutch, it is likely that one of these two common issues is the problem. The other most common problem that wears out clutches is resting a foot on the clutch pedal while driving.
If you allow a foot to rest on the pedal while going down the highway, it can let the clutch slip slightly and wear it down over time. Be sure to always rest your feet on the floor and not on the pedals.
Clutches are also only rated for a specific level of power, and if you plan on modifying your car to make more, it can wear out the clutch faster than normal or cause damage to the clutch, requiring the installation of an upgraded clutch.