Why is the clutch too hard?
3 Answers
Clutch being too hard refers to feeling very heavy when pressing the clutch pedal. The reason for a hard clutch may be that the pressure plate spring of the clutch is too stiff. The release bearing needs to press against the pressure plate spring of the clutch. Below is a detailed introduction about automotive clutches: Overview: The automotive clutch is located inside the flywheel housing between the engine and the transmission. The output shaft of the clutch is the input shaft of the transmission. While driving, the driver can press or release the clutch pedal as needed to temporarily separate and gradually engage the engine with the transmission, thereby cutting off or transmitting the power input from the engine to the transmission. Principle: The driving and driven parts of the clutch rely on the friction between contact surfaces, or use liquid as a transmission medium, or use magnetic transmission (electromagnetic clutch) to transmit torque, allowing temporary separation and gradual engagement between the two parts, while permitting mutual rotation during the transmission process.
I've been driving manual transmission cars for ten years, and the issue of a stiff clutch pedal is definitely not something to take lightly. Deteriorated fluid in the hydraulic system can cause the pedal to feel rough, especially in the humid weather common in southern regions. First, check if the fluid level in the clutch master cylinder reservoir is low and look for any signs of leakage around the hose connections. Last month, I just replaced the seals inside the master cylinder, and upon disassembly, I found the rubber rings had aged and cracked. If you hear a squeaking noise when pressing the clutch pedal quickly, it's most likely the release bearing failing. Honestly, repairing this requires dropping the transmission, and nowadays, labor costs far exceed the price of parts. If the steering wheel vibrates in sync with the clutch pedal, that means the clutch friction disc is worn to its limit—this must be replaced immediately, as further wear can damage the flywheel.
I'm a long-haul trucker, and years of clutch pedaling have left my knees with chronic issues. When the clutch suddenly gets heavy during hauling, the first thing to check is the pedal mechanism. Bend down and take a look at the pedal pivot—trucks often get sand and gravel stuck in the spring gaps. Last time, my truck had a dry, unlubricated linkage bushing grinding away, making each press feel like a rusty door hinge. Here's a quick tip: use a long-handled screwdriver to press against the clutch slave cylinder while someone steps on the pedal. If the pushrod travel is less than two fingers' width, the slave cylinder is likely toast. Nowadays, many new models don’t even use a slave cylinder—they rely on electronic clutch actuators. But my old rig, with some patching up, can still clock another 300,000 kilometers.
