How does the Torque Converter in the automatic transmission work?⚡Electric & Hybrid Vehicle Repairs⚡

Summary

This episode of a soft electronics series delves into the structure and operation of torque converters in modern automatic transmissions. It explains how torque converters function as fluid couplings, transferring engine power to the transmission while aiding in smooth gear shifts, reducing vibrations, and preventing costly repairs. The video also covers the repair process, diagnosing common faults, such as vibrations and difficult vehicle starts, and highlights the importance of using high-quality components. Emphasis is placed on precision during disassembly, cleaning, and reassembly, with a focus on restoring factory quality and ensuring optimal performance.

Takeaways

• 😀 The torque converter is a fluid coupling that connects the engine and transmission, increasing torque during driving.
• 😀 One of the main functions of the torque converter is to help smooth gear changes and neutralize engine vibrations.
• 😀 The torque converter operates by transferring fluid between the pump, turbine, and stator, creating rotational motion.
• 😀 Modern torque converters feature two modes: torque converter mode and lock-up mode, with the latter offering a firm connection between the engine and transmission.
• 😀 Common signs of a malfunctioning torque converter include periodic vibrations, noises, and difficult car starts.
• 😀 Regular maintenance and repairs are essential to prevent costly damage to the torque converter and associated components.
• 😀 Diagnostics and repair of the torque converter begin with a glycol test, followed by draining the oil and disassembling the gearbox components.
• 😀 If issues like metal shavings are found, further checks are conducted to diagnose the cause and ensure no damage to other parts of the gearbox.
• 😀 Incorrect repairs and low-quality parts, such as plastic clutch discs, can result in further damage and component failure.
• 😀 After repairs, the torque converter is thoroughly cleaned, measured for balance and alignment, and rebuilt with original parts from reputable manufacturers.

Q & A

What is the primary function of a torque converter in a vehicle's automatic transmission?

The primary function of a torque converter is to act as a fluid coupling between the engine and the transmission, transferring engine torque to the transmission, helping with smooth gear changes, and neutralizing vibrations and fluctuations from the engine.

How does a torque converter increase torque from the engine to the transmission?

The torque converter increases torque by using hydraulic fluid to amplify the power from the engine, particularly when the vehicle is moving and driving off. The fluid is directed through various components like the pump, turbine, and stator, which work together to transfer the energy efficiently.

What role does the stator play in the functioning of the torque converter?

The stator helps optimize the fluid flow by changing its direction before it reaches the pump blades, increasing the fluid's velocity and improving torque efficiency. It also prevents certain movements by locking the bearing and contributing to the converter's performance.

What happens during lock-up mode in the torque converter?

During lock-up mode, the torque converter creates a firm connection between the engine and the transmission, causing all components to rotate at the same speed. This mode is activated once a certain speed and acceleration threshold is reached.

What are the most common signs of a defective torque converter?

The most common symptoms of a defective torque converter include constant or periodic vibrations and noises from the gearbox, difficulty when the car starts off, and potential issues with the lock-up mechanism or damaged mechanical components.

What is the significance of the glycol test performed on a torque converter?

The glycol test helps determine if any harmful glycol has entered the system, as it can have a fatal effect on the friction elements in the transmission. If glycol is present, it requires further disassembly and checking of the gearbox to identify any damage.

What steps are taken during the repair of a torque converter?

During the repair process, the torque converter is disassembled, cleaned, and checked for metal shavings or damage. Components like the housing, pump, turbine, and stator are inspected for wear and tear. Worn parts are replaced with high-quality components, and the converter is reassembled, tested, and balanced before being returned to the vehicle or customer.

How can incorrect repairs or low-quality parts affect the torque converter?

Incorrect repairs or the use of low-quality parts can lead to issues like damaged clutch discs, imbalance in the converter, or malfunctioning of the lock-up mechanisms. This can cause further damage to the torque converter and the automatic transmission system.

What happens if there are metal shavings in the torque converter?

The presence of metal shavings indicates potential damage to internal components of the torque converter or transmission. It is essential to thoroughly inspect the gearbox for the cause of the shavings and address any issues to avoid further damage to the system.

What are the potential risks associated with a malfunctioning stator bearing in a torque converter?

A malfunctioning stator bearing can negatively affect the flow control between the pump and turbine, causing improper fluid dynamics within the torque converter. This can lead to reduced efficiency, increased wear, and potential damage to the torque converter and the transmission system.