Your vehicle is made up of thousands of moving parts. One of them is a thin metal disc that facilitates the transfer of power from the engine to the transmission. Referred to as the flex plate or flywheel, this crucial powertrain component also enables you to start the engine by just turning a key. So let’s take a closer look at the car flex plate, and answer the question “can I drive with a cracked flex plate?”.
What Transmission Do I Have?
What is a flex plate?
A flex plate is a thin metal round disc that mounts to the rear of the engine crank shaft. The outer edge is a ring gear that the starter motor mates to. Whenever you turn the ignition key, the starter motor spins the flex plate, which turns the crank shaft and causes the engine to start.
The flex plate is also the mounting point for the torque converter. As the crankshaft spins, that rotational energy is transferred into the torque converter, which creates the hydraulic pressure needed to operate the automatic transmission and send power to the drive wheels.
Cracked flex plate symptoms
- The symptoms of a bad flex plate are as follows:
- The starter makes an unusual whining noise when you’re trying to start the engine
- The starter seems to have difficulty starting the engine and can bog down
- There is a pronounced knock when you shift from park into reverse or drive
- Engine runs rough
- There is knocking/grinding/chirping/rattling sounds coming from the rear of the engine when it’s idling
- Poor performance
- Poor fuel economy
What should you do?
A cracked flex plate is a very serious issue, and should be addressed immediately. Expect the flex plate replacement cost to be between $900 – $1500, depending on the vehicle. Obviously it could be more if you drive a performance or luxury vehicle.
What Transmission Do I Have?
If the flex plate is damaged, it may have damaged the bearings inside the torque converter. So make sure to have your mechanic check that out.
