How to Know If Your Transmission Torque Converter Is Bad?
The horsepower generated by a car or truck motor is transferred to the wheels through either a clutch or a torque converter. An automatic transmission has a torque converter; a standard transmission has a clutch. When a torque converter goes bad in an automatic transmission, it can reduce your ability to drive safely. You may think the whole transmission needs repair, but it might only be a bad torque converter.
- Difficulty:
- Moderately Easy
Instructions
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1
Sit in the driver's seat. Turn the engine on using the key and let the vehicle warm up for at least two minutes. After the car is warm, press down on the gas pedal to rev up the engine two times. Let the engine come back to idle, then shift the transmission into drive while simultaneously time pressing down on the brake pedal.
Listen and feel how the transmission engages into drive. A bad torque converter will announce itself with a clicking sound when engaged, due to a broken sprag gear. The transmission may also lurch into gear due to an improper flow of transmission fluid caused by a bad torque converter.
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Shift through all the gears, including reverse, at a standstill before moving on to the driving portion of the torque converter test. If there is enough reason not to continue on with a test drive after running through all the gears standing still, seek to repair the problem before driving.
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3
Place the transmission back into park after testing all forward and reverse gears standing still. Begin a test drive to listen and feel for the other signs that will let you know if your transmission torque converter is bad.
From a stopped position, place the transmission into drive and attempt a high acceleration away from the starting point. Go far and fast enough to shift through all the forward gears without hitting the overdrive gear. During acceleration, feel and listen for sluggish response, high revving of the engine and the obvious clicking sound that a bad sprag in the torque converter will report back with. A bad torque converter does not produce the right power under slower speeds and will make a clicking sound when shifting.
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Tips & Warnings
Drain the fluid from the transmission and torque converter prior to testing. Many torque converters have a drain plug, but many do not. Transmission fluid can be broken down by heat and age, reducing its ability to work properly. Only remove half the old fluid on extremely old automatic transmissions that actually rely on the grit in the fluid for the transmission to work as well as it does. A broken sprag in a torque converter can be fixed before causing damage to the gears inside the transmission if caught early on.
Broken transmission parts and internal torque converter gears can become so damaged that the vehicle can not be driven safely on the road. Know that a test drive may leave you stranded down the road if the torque converter is bad and it breaks completely.
