Car Clutch Problems: 4 Most-Common Issues & Solutions

When it comes to clutch problems, it can be hard to distinguish between needing simple repairs and full rebuild jobs.

One small component can make the clutch assembly fail to work correctly, so understanding how the system works can help to know what to diagnose and fix.

We’ve gathered the most common clutch issues together and a solution for each. This will help you stay informed on clutch systems and how to repair them quickly.

#1 – Your Clutch Gradually Fails To Work

Every new car with a manual transmission rolls off the dealership lot with a new clutch assembly in working order.

Clutches last on average about 75,000 miles, so if you own your car long enough, you will need to have the clutch replaced at some point.

The system has multiple components that work together, so any one of them could cause the complete clutch assembly to stop working.

How to Fix It

Three main components in the clutch assembly get all the attention:

• The clutch disc
• The pressure plate
• The throw-out bearing

These three make up the connection between the engine and the transmission and allow power to be transmitted through the car’s drivetrain.

The clutch disc has a surface on each side of the disc that wears out over time. One side contacts the flywheel on the back of the engine, and the other side contacts the pressure plate in the clutch assembly. The clutch disc surfaces wear out due to contact and eventually lose their ability to provide friction between the surfaces.

Foreign material on the disc surface can also prevent full engagement. When that happens, the clutch slips and the engine revs up without turning the transmission shaft. It’s time to replace the clutch assembly with a new one.

While these three main components in the system receive the most discussion, other parts can cause the clutch to gradually fail.

The system is either mechanical using a cable to actuate the pressure plate movement, or it is hydraulic using a cylinder to move the lever arm.

A cable can stretch over time and cause limited movement of the pressure plate. It can prevent the clutch disc from disengaging with the flywheel.

A hydraulic system uses fluid pressure to move a cylinder, which can have a leak or air in the fluid line to prevent movement. The fluid quantity can also be low, which will prevent the cylinder from moving. You will need to adjust the cable length or the attachment points to restore actuation unless it needs to be replaced with a new cable that hasn’t stretched.

Hydraulic fluid needs to be checked to ensure the system is full, the fluid isn’t full of contaminants, and there are no leaks in the hoses. If those issues are causing a failing clutch, the fluid may need to be replaced, leaks fixed by replacing parts, and then the system bled to remove the air trapped.

The last issue that can cause gradual clutch assembly failure is worn or damaged components in the system. A bent lever can prevent the clutch from disengaging correctly, and a failing cylinder (either master cylinder or slave cylinder) can also prevent the clutch disc from disengaging. This will prematurely wear the clutch disc surface.

If you find the clutch is gradually slipping, be sure to also check the transmission mount isn’t damaged or worn out. It can also cause gradual failure requiring the clutch assembly to be replaced.

#2 – The Clutch Assembly Fails To Disengage

When you press the clutch pedal in, you expect that the clutch assembly will easily disengage, and you can then shift gears. Sometimes that doesn’t happen, and it’s not a gradual change. If the clutch assembly doesn’t work, something major has happened.

How to Fix It

The clutch assembly is binary by nature in that it either works or it doesn’t. If your clutch won’t disengage, something is adjusted incorrectly, or it is broken. Finding out why will just take a few steps of diagnostic work.

The clutch assembly is either mechanical or hydraulic.

Mechanical assemblies will use a cable that connects to the clutch pedal and the lever on the transmission. This cable can break, stretch, or come loose at one end and prevent the clutch from actuating.

A hydraulic assembly uses a master and slave cylinder combination connected to the clutch pedal and level to actuate the clutch assembly. These cylinders can fail, the hydraulic lines can develop a leak, or air can become trapped in the system causing the clutch to suddenly stop working.

The last issue that causes a failure to disengage is the throw-out bearing becoming lodged on the input shaft. This bearing slides on the input shaft using a thin layer of grease for lubrication. If it corrodes due to wear, it may stick to the input shaft and cause a failure to disengage.

Linkages can be adjusted if the cable has stretched, or it may need to be replaced if it has stretched beyond useable limits.

Hydraulics can be bled if air is trapped in the system, or failed components can be replaced. The throw-out bearing requires the transmission to be removed for an inspection, and it can be replaced if it’s worn out.

#3 – Your Clutch Assembly Won’t Engage

Your clutch pressure plate forces the clutch disc to contact the flywheel connected to the engine. The friction between these surfaces allows the engine power to turn the input shaft to the transmission and move the car.

If it doesn’t engage, the car won’t move, and you’re stuck in traffic going nowhere.

How to Fix It

Clutch engagement requires two things to happen:

1. The clutch assembly to move and apply pressure to the clutch disc.
2. The disc to have enough friction to turn with the engine flywheel.

If you don’t have both, the transmission shafts won’t turn the gears to move the car.

The movement in the clutch assembly is actuated by the cable or hydraulic line connected to the clutch pedal. These move a fork that pushes the clutch pressure plate into the clutch disc. The linkage must be adjusted correctly and move freely, or it can prevent the clutch disc from fully engaging with the flywheel.

Secondly, once you have contact between the clutch disc and flywheel, it needs to have dry contact.

The main seal on the engine can leak oil and cause the clutch disc to slip against the flywheel. The clutch disc surface can also wear out and cause a slipping condition. Slipping can overheat the clutch disc and flywheel, which warp the surfaces and also prevent full engagement.

Leaks must be repaired, and then the surfaces can be cleaned to remove any foreign material or oily residue. Worn components such as the clutch disc, the pressure plate springs, or the linkage bushings can be replaced if they are worn out or broken.

In most cases, the complete clutch assembly (pressure plate, disc, and throw-out bearing) is changed at the same time.

#4 – Your Clutch Is Noisy

If your clutch works, everything must be great, right?

Not necessarily.

Your clutch can function correctly, but it may make too much noise. Noise is often a product of missing lubrication or a worn component in the system.

You don’t want lubrication on the surfaces at the flywheel, clutch disc, or pressure plate, but you do want it everywhere else. A chattering noise can come from a bad pilot bushing in the end of the crankshaft or a worn-out throw-out bearing when the clutch pedal is pushed in and allowed to return to the top of its stroke.

A rattling can be heard if the clutch release fork is loose or the clutch pressure plate springs have worn out and aren’t applying sufficient pressure to the clutch disc.

You may also find worn linkage bushings allowing cables to rattle or that the cable has frozen in place due to a lack of lubrication.

Stuck components and noisy contact points can be lubricated with grease, and that may quiet them down.

Worn components will need to be replaced, which may require the transmission to be removed from the car depending on their location.

You should check for loose fasteners that can allow components to vibrate and cause premature wear too. The clutch assembly is a simple system with multiple moving parts, and fixing it usually isn’t too difficult.

Please also read our article all about car voltage drop issues (with solutions).

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