Flywheel Machining

Every vehicle with a manual transmission has a device called a flywheel. Flywheels are heavy, balanced metal disks attached to the back of the engine, storing rotational energy and integrating with the vehicle’s clutch. Flywheels have a friction surface for the clutch to engage with and teeth to engage with the starter motor.

Flywheels also help keep your engine running smoothly even when torque varies during gear changes. Without the momentum of the flywheel, the engine would likely stall when engaging the clutch. This is because the engine speed would drop too quick without the angular momentum of the flywheel.

Both the flywheel and the pressure plate of the clutch have surfaces that are designed to engage through friction. If you are going to the expense of replacing your clutch, it is essential to check the flywheel and get it machined depending on if it is damaged. The cost of flywheel machining is not high, so most of the time, it is worth doing.

Note: most clutch manufacturers void your warranty if you don’t have your flywheel machined.

Some symptoms of flywheel and/or clutch problems are:

Clutch chatter.

Is the vibration of the clutch. If you are experiencing a lot of vibration through the clutch pedal, your flywheel may be damaged. This can be caused by driving too long on a clutch that needs replacing. The excessive heat can damage the surface of the flywheel and even warp it. If you wear your clutch down to the rivets, it will damage the flywheel. If your clutch is down to the rivets, you will hear it.

Burning odour.

A burning smell can be attributed to many causes. A bad flywheel and/or clutch can be a source of this smell. Seek professional advice if this occurs.

Slipping gears.

Gear slipping occurs when shifting to a new gear the engine speed (RPM) increases faster than your speed, then you may have a clutch and/or flywheel problem. If you allow this to persist, you can cause significant damage to your clutch and flywheel.

Cannot change gears.

If you can’t change gears, the flywheel is usually in bad shape. It can also mean the clutch and other transmission parts are damaged.

Engine Vibrations.

Even with the clutch engaged, an unbalanced flywheel can vibrate the whole powertrain. This can occur when bolts are not torqued to the correct specifications or when required; a thread locker is not used. A loose or disintegrating flywheel contains a great deal of momentum and is extremely dangerous if it comes loose when driving. Best to leave to the experts.

Trouble starting the engine.

When starting your car, the starter motor engages with the teeth on the flywheel. Usually, the gears on the starter motor will fail first; however, it can damage the teeth on the flywheel. This usually requires the flywheel to be replaced.