Thread: Torque Converter Question

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I have a 68 chevy truck with 350 engine and 350 turbo trans. with stock torque converter.

My question is regarding what a torque converter does and how to know if it is going out?

When my transmission shifts to 3rd, the engine power drops off even though I have it floored.

Thanks for your help,

Soldout

It essentially acts like the clutch in a stick shift car. It is a fluid coupling that allows the engine to disengage from the transmission when the car needs to come to a stop. Without it, the car would continue to move.

When you are idling, very little fluid is being pumped into it, but the harder you push the gas, the more fluid you get, and the car begins to move.

When you hear of a hi-stall converter, it means the rpms can go higher before it starts to move the car forward. If you have ever brake raced a car (sit there holding the brake down while stepping harder on the gas) you have experienced a place where the car wants to move. With a hi-stall converter, that rpm spot is moved higher, so you can have a cam that is really lumpy, and it won't want to move the car forward at the higher rpm levels.

This is a little simplistic, but basically how it works.

Don

PS: Something else is going on with the 3rd gear issue, not sure what though.

Here is a fairly decent link regarding the operation of a torque converter. It does a good job covering the basics in what should be fairly easy to understand language.

http://auto.howstuffworks.com/torque-converter.htm

If I remember correctly, it also has some decent animation that will show you what's happening when the auto-tranny shifts as well.

As for the power loss after shifting to third, it depends. Is there any stumbling or shuddering of the tranny?

Dutch