The clutch fork is responsible for moving the throw-out bearing when you push down on the clutch pedal. A bad clutch fork will cause problems with the operation of the clutch.
As a general rule, the symptoms of a bad clutch fork include trouble changing gears, noises from the clutch when the pedal is pressed, a burning clutch and a heavy or stiff clutch pedal. A bad clutch fork will cause premature clutch plate wear, and should be replaced during a clutch replacement.
The clutch fork is not usually the weak point in the clutch, and won’t normally fail by itself. Usually a bad clutch fork is caused by excessive force on the clutch caused by damage elsewhere in the clutch. If the clutch fork fails, it can be expensive to repair and you may need to get the entire clutch replaced as part of the repair.
5 symptoms of a bad clutch fork – how do you know if your clutch fork is bad?
- Trouble changing gears
- A burnt clutch
- Heavy or stiff clutch pedal
- Rattling noises from the clutch when the pedal is pressed
- No clutch pedal resistance
The clutch fork is designed to operate under extreme pressures often in excess of 1500 lbs. They are usually made from hardened steel that can resist high temperatures and pressures, but over time they can weaken and sometimes crack or bend.
It’s best practice to replace the clutch fork during a routine clutch plate replacement, especially if it’s a high mileage vehicle. Even if the clutch fork has not failed, it can start to wear, especially at the point where the fork pushes against the throw out bearing.
Here are the symptoms of a bad clutch fork.
Symptom 1: Rough Gear Changes
The most common sign of a bad clutch fork is trouble changing gears. The clutch fork is an essential component in the gear change mechanism. Its job is to push the throw out bearing against the pressure plate to release the clutch plate so that a new gear can be selected.
A bad clutch fork will not operate as smoothly as it should when the clutch pedal is pressed. Since the clutch fork operates under such extreme pressure, even minor damage to the fork can affect the operation of the clutch. For example, if the clutch fork is slightly bent then it will not have the same range of movement when the clutch pedal is pressed. This will stop the throw out bearing from moving far enough to full disengage the clutch when changing gear. This will make it difficult to change gears and can make the gear selector feel rough or stiff.
Symptom 2: A Burnt Clutch Plate
Another common symptom of a bad clutch fork is a burnt clutch plate. A damaged or broken clutch fork is not going to fully disengage the clutch when the pedal is pressed. If the clutch fork is not fully disengaging the clutch, then this can cause clutch slippage whereby the clutch plate rubs against the spinning flywheel causing it to heat up and burn.
The symptoms of a burnt clutch include a foul burning smell (especially when changing gears), erratic engine acceleration, difficulty changing gear and a stiff clutch pedal. If the clutch fork is not repaired then this will lead to clutch failure fairly quickly. A burnt clutch plate can also cause damage to the flywheel and the pressure plate.
Symptom 3: Changes to the Clutch Pedal Feel
The clutch fork is attached to the throw out (release) bearing at one end and the slave cylinder at its other end. Most modern cars use a hydraulic clutch system, where fluid is pumped under pressure by a master cylinder to a slave cylinder. This fluid pressure forces the clutch fork to move forwards on a pivot, moving the release bearing with it.
The ‘feel’ of the clutch pedal will change if the clutch fork is loose or bent. It may feel stiffer if it no longer has the same range of movement, or it may feel lighter if it has become loose or has disengaged from the release bearing.
Symptom 4: Vibrating Clutch Pedal or Noises From The Clutch
Another very common symptom of a bad clutch fork is a vibrating clutch pedal. As explained above, the clutch fork is held in place under pressure and pivots on a central axis when the clutch pedal is pressed. When it pivots, it moves the throw out bearing inwards or outwards.
If the clutch fork is damaged or bent, it may no longer be tightly held in place and this can cause vibrations that can travel back up through the clutch pedal. These vibrations can be created by the clutch fork moving about on the central pivot, or it may be vibrations from the throw out bearing if it is no longer held firmly in place.
Damage to the clutch fork can also lead to damage to the rest of the clutch assembly. If the pressure plate is no longer held under sufficient pressure, this can lead to a slipping clutch that can burn the clutch plate and warp the flywheel. A warped flywheel will create even more vibrations, further compounding the problem.
Symptom 5: Clutch Pedal Dropped To The Floor
If the clutch fork has become completely disengaged from the slave cylinder or the throw out bearing, this can cause the clutch pedal to become overly soft and it may even drop to the floor.
On most modern cars the clutch is a hydraulic system that operates under the pressure generated by the clutch fluid being pumped by the master and slave cylinders. Older vehicles don’t use a hydraulic system, but use a clutch cable instead to operate the clutch fork.
A bad clutch fork can put extra pressure on the clutch cable, causing it to snap and this can also cause the clutch pedal to drop to the floor, losing all resistance.
1. What Does A Clutch Fork Do?
The job of the clutch fork is to move the throw-out bearing back and forth on the input shaft of the transmission. The throw-out bearing holds the pressure plate in place by putting pressure on the diaphragm spring located between the pressure plate and the clutch disc.
The movement of the throw-out bearing facilitates the disengagement of the clutch friction plate when the clutch pedal is pressed. The pressure plate is held tightly in place against the clutch plate with the help of pressure plate springs.
Pressing on the clutch pedal pushes the clutch fork against the throw-out bearing that in turn pulls the diaphragm spring fins backward so that the pressure plate moves away from the clutch plate. This allows the gear change to take place before the pressure plate is released and the power from the engine can once again be transferred to the transmission and onto the wheels.
If the clutch fork is not operating smoothly, or has broken completely, then gear changes are either going to be difficult or not possible at all.
2. How much does it cost to get a clutch fork replaced?
A clutch fork replacement can cost in the range of $400 to $700. The clutch fork itself can cost as little as $30, but the majority of the cost is associated with the labor involved in replacing the fork.
It is best practice to replace the clutch when the clutch fork has been replaced, especially if the clutch has not been replaced recently. A bad clutch fork can cause damage to other clutch parts such as the clutch plate or flywheel, so it is safer to replace everything when getting the bad clutch fork replaced.
If the entire clutch assembly is being replaced, this can increase the cost to over $1000.
3. What causes a clutch fork to break?
A clutch fork can break if it is put under more pressure than it is designed to handle. One of the most common reasons for this to happen is if some other part of the clutch assembly becomes damaged that leads to excessive vibrations of stiffness especially when the clutch is in use. Common reasons for a broken clutch fork include a bad throw out bearing, an overly stiff pressure plate and a warped flywheel.
Sometimes a broken clutch fork can be caused by a defect in the clutch fork from when it was manufactured. This could be something like a hairline crack or an issue with the quality of the materials used in the manufacturing process. A manufacturing defect may go unnoticed during installation, but it could get worse over time and eventually lead to failure.
In some cases a broken clutch fork can occur if it is not installed properly. Installation issues such as an overly tensioned clutch mechanism can put too much pressure on the clutch fork, causing premature failure.