how do i know if my torque converter lock-up kicks in?

[dmafanp]

what shoudl i be watching for ,, i have tried looking for an extra downshift with no luck im in my top gear going the slowest possible speed 50 kmph and i dont know what to do next or if im missing an efficiency zone i dont know about,, im a newby

[Cobb]

Try giving light throttle and see what speed the revs do not change, but the tone of the exhaust or engine does.

Watch rpms too and try in 5 mph ranges speeding up, then coasting and looking for an extra shiftor drop of 500 rpms for no reason.

[jeff88]

Is there a way to use a gauge/monitor to tell you when it is locked? (e.g. will a scangauge or similar have a "gauge" to tell you.) Or is there a way to install an aftermarket sensor that can turn an LED on/off in the cabin (i.e. light on, TC locked)?

[Baltothewolf]

torque conver? Excuse my ignorance but is that thing the extra 'gear' in automatics so to speak that when between 45-55mph and low engine load, drops the rpm from say 2600-2k? (At 55mph).

[niky]

Depends on the auto, but yes, when the torque converter locks up, the revs stay steady with speed. Many modern cars will let the converter slip while accelerating, then lock it up when you let off the cruise.

[Frank Lee]

how do i know if my torque conver kicks in?

With the engine running and the trans in gear, you know the torque converter has kicked in when the car starts to move.

The torque converter lock-up clutch is what you are wondering about. Banks Power | Understanding Torque Converters

[Baltothewolf]

Originally Posted by Frank Lee

With the engine running and the trans in gear, you know the torque converter has kicked in when the car starts to move.

The torque converter lock-up clutch is what you are wondering about. Banks Power | Understanding Torque Converters

Wow, thanks for that! I have always wondered how a auto tranny works and now I know (for the most part).

[Cobb]

You could run an led or indicator lamp to it, but it doesnt show on a sg2 or the other guys product.

[MetroMPG]

It doesn't show on the default OBD-II gauges, no.

[gone-ot]

ANALOGY: a "torque converter" is like two fans facing each other, one powered (input) and the other not powered (output).

The "air" from the powered (input) fan forces the unpowered (output) fan to turn/rotate, but not at exactly the same rpm, with the difference in their rpms being called "slip"...the more slippage there is, the greater the torque-ratio.

Basically the same process occurs inside the transmission torque-converter, except transmission FLUID replaces the AIR in the above example.

Thus, slight changes in engine RPM, not accompanied by equal changes in vehicle VELOCITY, means the torque-converter is NOT in lock-up. Think of lock-up as 1:1 gearing, ie: zero torque-converter slippage.