|
Converter Basics |
Scott Simpson
|
What is it? |
The torque converter is the piece that connects the output of the engine to the input shaft of the transmission. It is a round gadget that looks like an oversized donut and bolts to the flexplate (also referred to as the flywheel.) The stock Turbo Regal has a 12" diameter converter stamped D5 D5 D5 all the way around the face of the converter. It is a unique special high stall converter from the factory. The factory stall speed is approximately 2200 RPM.
Note: many transmission shops may be unaware of this special converter and could possibly swap yours for a standard 12" torque converter that stalls at about 1800. How can you tell? With such a low stall torque converter, the 250+ HP V6 won't be able to break the tires loose on the street. (Something to watch out for when buying a TR ) |
How Does it Work? |
Through the use of fins on the inside of the torque converter and transmission fluid getting pumped into the converter at fairly high pressures, the input and output speeds of a torque converter can be vastly different, or the same.
A 12" or 9" converter refers to the diameter of the unit itself. In general, a smaller converter will have a higher stall speed. To oversimplify, stall speed refers to how high you can rev the engine before the torque converter will no longer "freewheel" and attempt to turn the tires. But since the tires don't want to turn over because of friction, the motor begins to stall. A lockup converter will have a clutch disc inside of it (much like a manual transmission) which, when the torque converter is "flooded" with tranny fluid, will lock up (same as taking your foot of the manual trans clutch pedal.) To flood the torque converter, fluid needs to get into the converter at a much higher rate. To do so, a Torque Converter Clutch (TCC) solenoid inside the valve body of the trans opens a plunger which creates an additional fluid path that "floods" the torque converter with additional tranny fluid...locking up the clutch mechanism inside the torque converter. The TCC solenoid is activated by the ECM based on 3 engine inputs, VSS, TPS and gear indication. A sticking solenoid will cause the transmission to bog down the engine during deceleration. To replace it, one needs to simply remove the trans pan and remove the two bolts that hold it in place and disconnect the wires to the 3rd and 4th gear indicators. A new solenoid comes with new wires. |
Which One Should I Use? |
Converters come in several "flavors" ...
|
Last updated: