lock up / non lock up stall converter

[jamepc]

so.. what's the differance?

[tobs440]

ok you know when you are driving fast (on the track)....and you go into overdrive then you get on last little rpm drop... that is the converter going into lock-up. if you tap the breaks it comes out and the rpms rev up again...it has to do with the overdrive, my deffinition isnt very ughhhh technical as most would say but that is the jist of it.. you thinking of getting one?? i have the 166k sitting hre right next to me screaming put me in put me in....

[HankL]

The non-lockup torque converter is like the old style used in muscle cars of the 1960s and 1970s. It does not have a clutch built inside of it.

The lockup clutch was added in the late 1980s to improve gasoline mileage.

The non-lockup torque converter will probably be much more durable if you hot rod your truck, or increase the HP of the engine greatly - like with a supercharger.

The penalty in MPG is probably about 10-15%.

[jamepc]

Hey - Thanks for the info.
When I raise the rear off the ground the wheels spin @ about 5 mph in neutral. Could this be pre-mature lock up? I have to rebuild the tranny anyways and it is a new MP converter in there now, but I was wondering if there was anything speficic I should look for while I'm in there. My other guess is that it's the rear clutch sticking. Any other ideas?

Thanks

[Walkercolt]

jamepc, that's about normal. With NO load on the driveline, the engine idling can turn the wheels. Good example is motorcycles. In NEUTRAL, with the clutch PULLED IN, most bikes will turn the rear wheel at idle. You can take a wrench and put it against the tire, and stop it with almost no effort. Just the "sympathetic vibrations" of the engine are enough to rotate the clutch, the transmission parts and move the chain, thus, the rear wheel. Now if your truck crawls at 10 MPH at idle on level ground, you've got a problem.

[disavowed]

the way i under stand it is it is when your converter goes to a 1 to 1 ratio.