How it works
This torque converter labeling exercise has seven numbers. The engine side is at the left and the shaft leaves at the right. Numbers 1, 3 and 6 stand down the left, and 2, 4, 5 and 7 down the right.
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Torque converter word bank
Seven names, in alphabetical order: housing (cover), impeller (pump), input shaft, lock-up clutch, one-way clutch, stator, turbine.
Numbers that get swapped
2 and 3 are the two vaned halves that face each other: 3 is the half nearer the engine (turbine), 2 the half in the rear shell (impeller). 4 is the small vaned wheel between them (stator), and 5 the dark block it sits on, nearer the shaft (one-way clutch). 6 is the thin disc just inside the front wall (lock-up clutch). The wall itself is part of 1 (housing).
- When marking, pump is right on line 2, overrunning clutch on line 5 and torque converter clutch on line 6.
- The converter is cut in half along its shaft, so every part but the shaft shows twice, above the shaft and below it.
Questions and answers
What is the difference between a torque converter and a fluid coupling?
A fluid coupling has two elements and cannot multiply torque. A torque converter has at least one more, the stator, which raises the output torque while the turbine is turning much slower than the impeller.
Where is the torque converter located?
Usually between the transmission and the engine's flexplate. Its equivalent in a car with a manual transmission is the clutch.
What are the three stages of torque converter operation?
Stall, acceleration and coupling. At stall the impeller turns and the turbine cannot, as when a car in gear is held on the brake. In acceleration the turbine gains on the impeller. In coupling it reaches about 90 percent of the impeller's speed.
How much does a torque converter multiply torque?
Most at or near stall. In most cars the ratio at stall is between 1.8 to 1 and 2.5 to 1. By the coupling stage the multiplying has all but stopped.