A good clutch can last your car between 50,000 and 100,000 miles. This depends on the make, model, and year of the vehicle as well as the type of clutch and your own driving habits. Stop-and-go traffic, towing heavy loads, abruptly engaging or “dumping” the clutch, and riding the clutch (keeping your foot on and halfway engaging) when decelerating are all factors that can lead to signs of clutch failure.
Sprag clutch failure symptoms are easy to spot if you pay attention to your vehicle. You’ll need to remain vigilant of noises, clutch pedal behavior, and performance to understand the problem and its source.
SPRAG CLUTCH FAILURE SYMPTOMS OFTEN INCLUDE:
- Clutch Pedal Makes Noises When Engaging and Disengaging
- Clutch Pedal Chatters When You Accelerate
- Clutch Pedal Pulsates
- Clutch Pedal Remains Stuck to the Floor
- Clutch Pedal Feels Loose or Spongey
- Clutch Pedal is Hard to Engage
- Transmission Makes A Grinding, Whirling or Chirping Noise in Neutral
- Grinding Occurs When Shifting Gears
- Can’t Get Transmission Into Gear
WHAT IS A CLUTCH? HOW DOES A CLUTCH WORK?
Before diagnosing your clutch problems, it’s important to understand what a clutch is and how it works in regard to your vehicle’s powertrain. A clutch is a mechanical component in a vehicle or other mechanical device that engages and disengages a powertrain or transmission between several rotating shafts.
The clutch connects these two shafts, allowing for either to lock together and spin at the same speed, or decouple and spin at different speeds. In most vehicles, the clutch sits between the engine and the main driveshaft, modulating torque and power from the engine to the wheels. Torque is simply any force applied at a distance. It’s measured in foot-pounds or newton-meters.
You need a clutch in your car because the engine spins all the time, but your car’s wheels don’t. To stop your car without stopping the engine, you need a way to disengage the wheels from the engine. Through the friction of the engine’s flywheel and the clutch disc, you can engage your spinning engine to a sometimes-spinning transmission and visa-versa.
Clutch pressure plate failure symptoms can occur when you aren’t engaging the clutch. The clutch springs push the pressure plate against the clutch disc. This presses against the flywheel and locks the engine to the transmission input shaft, causing both to spin at the same speed.
A Traditional Clutch Assembly Contains the Following Components:
- Clutch Disc – connects to transmission
- Release Mechanism (mechanical or hydraulic)
- Cable – connects between clutch pedal and fork
- Linkage – connects fork to pressure plate
- Pressure Plate – connects to clutch disc
- Flywheel – connects to engine
- Pilot Bearing – connects input shaft and clutch disc
- Release or “throw-out” Bearing
- Clutch Fork – modulates force between pressure plate and clutch via linkage
WHAT ARE THE SIGNS OF A SLIPPING CLUTCH?
If transmission shop mechanics refer to your clutch slipping, they mean that the clutch friction material is worn out. Your clutch only engages through friction, so if there’s no material there to provide that friction, then your clutch won’t engage properly. If your clutch is slipping, you’ll feel that as you release the pedal and accelerate, your vehicle will move slowly, while the engine revs higher. You may also notice the clutch releasing sooner than expected without much need for pressure.
Potential Causes Leading to a Slipping Clutch:
- Clutch linkage or cable needs adjustment because the cable is binding or the cable housing is filled with rust.
- Clutch linkage is bent, misaligned, or damaged.
- Pressure plate is weakened or warped.
- Clutch assembly is contaminated with oil due to your engine or transmission oil leaking.
- Broken motor mounts.
Keep in mind that if your clutch doesn’t release properly, it will continue to turn the input shaft. This can cause grinding, and prevent your car from going into gear. Some common reasons a clutch may stick are:
- Broken or stretched clutch cable – The cable needs the right amount of tension to push and pull effectively.
- Leaky or defective slave and/or master clutch cylinders – Leaks keep the cylinders from building the necessary amount of pressure.
- Air in the hydraulic line – Air affects the hydraulics by taking up space the fluid needs to build pressure.
- Misadjusted linkage – When your foot hits the pedal, the linkage transmits the wrong amount of force.
- Mismatched clutch components – Not all aftermarket parts work with your clutch.