Lock up converters

[1997chevydriver]

if you want I can take a vid tomorrow explaining what I just said

 

[Wildbill0088]

If we are talking about the 92 then yes it should have one. another way to tell if it's working or not is get up to 55 or so and hold it there then go to accelerate (not enough to make it shift out of OD) if RPMS climb without going faster than it is unlocked and not working

Well think that puts it in the not working category. So now what?

 

[1997chevydriver]

Most of the time.......... New torque converter. Sometimes it's just the wiring

 

[supertrucker1978]

how would an automatic transmission function without a converter that can lock and unlock

It would take me forever to explain how a torque converter works but not all converters lock up, This link will explain it.

http://www.classictrucks.com/tech/0810clt_how_torque_converters_work/viewall.html

Did the two foot driving at about sixty steady no difference in rpms when I ease on the brakes and the extra "shift" is nowhere to be found

Your truck has a lock up and it seems it isn't working. Could be a number of reasons, could be the lock up solenoid, could be the converter, could be something inside the transmission itself. With your converter not locking the heat created is doing damage to your transmission. Check out this link it will tell you how a lockup works and about the damage caused by it not working.

http://700r4.com/faq/whatlock.shtml

 

[Wildbill0088]

Well great yet another time bomb

 

[trx88]

i read it but it said nothing about lock up. my point is that if you have an automatic transmission and you come to a stop. you have to have a valve open and let fluid bypass and the pump circulate to take away some of the hydraulic torque applied to the inside turbine which gives power to the driveshaft. otherwise your spinning flywheel will take the hydraulic torque on itself and kill the motor. the term lockup describes this. now how can you have a torque converter that does not lock and unlock?

 

[trx88]

Coupling
The coupling stage is when the turbine is within about 90 percent of the pump speed. At this point, if your torque converter has a lockup clutch, it would engage and basically fix the turbine and pump together via a small clutch mechanism between the cover and turbine. Under lockup there is no slipping between the two halves of the converter and efficiency inside the converter as well as fuel efficiency goes way up-as much as 65 percent, according to some manufacturers. With today's crazy gas prices, you might wanna upgrade to an overdrive transmission with a lockup converter if you haven't already!


Read more: http://www.classictrucks.com/tech/0810clt_how_torque_converters_work/viewall.html#ixzz2JvXtpOtg

 

[trx88]

there i go

 

[1997chevydriver]

Coupling
The coupling stage is when the turbine is within about 90 percent of the pump speed. At this point, if your torque converter has a lockup clutch, it would engage and basically fix the turbine and pump together via a small clutch mechanism between the cover and turbine. Under lockup there is no slipping between the two halves of the converter and efficiency inside the converter as well as fuel efficiency goes way up-as much as 65 percent, according to some manufacturers. With today's crazy gas prices, you might wanna upgrade to an overdrive transmission with a lockup converter if you haven't already!


Read more: http://www.classictrucks.com/tech/0810clt_how_torque_converters_work/viewall.html#ixzz2JvXtpOtg

He has a trans with both lock up TC and OD already but the lock up portion of the converter has failed so it no longer locks like its supposed to.

Sent from somewhere in MN

 

[great white]

700r4 = lockup clutch in converter

4L80E = lockup clutch in converter

If you really want, a 92 can be modified with a simple switch to force lockup any time you choose. Its a fairly popular thing with 6.5 diesel guys who towto keep temps down and provide a bit of extra braking on downhill runs. Later years use a pwm signal so this type of thing won't work and need to be altered in the pcm calibration.

Use withn caution though, the clutch in the convertor is not meant for heavy abuse. Its relatively small and only meant to engage when the trick is already up to speed....