How to Turn the Flywheel in a Car

by Francis Walsh

If you have a transmission problem then you need to know one of two things. One, who to call to do it for you or two, how to turn a flywheel on an engine to get the transmission separated from the engine block. If you're thinking you want to get under your vehicle and do it yourself, then be prepared to spend some time underneath the transmission to get it done. The transmission uses a torque converter to transfer the spinning energy of the crank shaft to the transmission. Turn the flywheel in a car to get to the bolts that secure the torque converter to the flywheel to extract the transmission for repair.

Open the hood of the vehicle to access the engine. Stand on top of a small ladder so you can insert a socket and ratchet wrench into the front of the engine compartment where the radiator fan or main pulley is. Remove the plastic protective covering and shields that prevent the use of an extension bar on the ratcheting wrench after it has been secured into position.

Enter the vehicle's driver door and sit in the driver's seat. Communicate with your assistant under the vehicle as to the position of the flywheel and the placement of the bolts that need to be removed to separate the torque converter from the flywheel. After clearing away from any moving parts, the assistant will tell you if the movement of the flywheel was too little or too much.

Insert the ignition key and turn the engine over. The ignition will activate the engine starter. The starter uses the flywheel to crank the engine for starting. The downside to this motion is that it puts a strain on the engine, and the movement is erratic. Turn the flywheel with the ignition and starter until it is in place. The alternative way is to do it by hand.

Insert a socket on the end of the shaft to which the main pulley is attached . For older cars that have a radiator fan on them, attach a socket to the nut that secures the fan to the fan shaft and turn the nut clockwise. The engine may be too large to turn by hand with just a ratchet wrench and socket. For more leverage, slide an extension bar over the handle of the ratcheting wrench and attempt to turn the fan shaft clockwise using the bar.

Have an assistant make a mark on the transmission housing, which will place the bolts that need to be removed in the correct spot. Communicate while turning the engine by hand or by using the key and starter until the bolt is in position and they can be removed. Either technique works, but doing it by hand using a ratcheting wrench is the way to do it on any high-performance vehicles that might be damaged during the cracking of the engine with a starter again and again.

Tip

  • check Use a deep socket to grip the radiator fan or main pulley bolt while turning a car's flywheel. A short socket does not give the user enough distance away from the engine to maneuver easily. The short sockets also slip off easily, causing a knuckle buster you will want to avoid.

Warning

  • close Avoid turning the flywheel using the ignition if possible. The "dry" starts can create damaging heat inside the engine of a performance-level car and cause important gaskets to break down and leak in extreme situations.

Items you will need

About the Author

Francis Walsh has been working as a freelance writer since 2003. He has contributed to websites such as Shave, Autogeek and Torque & Chromeas, as well as provided content for private clients. Walsh has worked as a performance part-packer and classic car show promoter, now serving as crew chief for Nitrousfitz Racing.

Photo Credits

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