Manual transmission vehicles allow drivers to handle the gear shifting via the clutch.
The flywheel is an integral component of the clutch system in manual transmission automobiles. These can be manufactured in single or dual flywheel systems and work to reduce vibration and maintain gear integrity while the driver is operating the transmission via the clutch. When the flywheel begins to fail, it may be a symptom of larger problems in the transmission such as oil fouling or a cautionary reminder that the driver has been operating the clutch outside acceptable parameters.
Vibration Through the Clutch
Some vehicles use a two-part flywheel system called a “dual mass” flywheel. When these parts or the spring mounts around them begin to fail, the flywheel system will lose its ability to reduce vibration caused by clutch operation. The driver will experience this as increased rumble and vibration through the floor of the vehicle and through manipulation of the clutch when shifting gears.
A smell like burnt toast is a prime indicator that the flywheel is in need of repair. The smell is due excessive heat in the clutch facings, which is caused by riding the clutch, allowing the gears to slip when in traffic or idling. Over time, if the clutch and flywheel are not allowed to cool, it will ruin the flywheel along with the rest of the system, including the pressure plate and disc.
In dual mass flywheel systems, a symptom of failure is often gear slippage. This can be caused by oil contamination in the inner workings of the dual flywheel or through increased friction due to plate grinding. The driver will notice an intermittent issue with up-shifting where the vehicle may accelerate poorly or be unable to traverse to the next gear or make the shift, but not be able to hold and quickly slide back into the previous gear.