Engine/Transmission (1998.5 - 2002) TC lockup question

[Tractorat]

I have a question regarding TC lockup. I dont really notice anything if/when the TC locks up. Is there a way to tell if it is indeed locking up ?



Also, I notice in the manual that TC lockup is supposed to happen at calebrated speeds, but it doesnt say what that speed is. Can anyone enlighten me ?



Thanks for your help,

TRat

 

[Graphic man]

your trans shifts 1, 2, 3, lock-up 4 lock-up... . 3-4 shift is lock to lock



you will feel the lock-up when you hit the switch... . you know it's locked when you slow down if you forget to turn the switch off



your trans will go into OD-lock at around 55mph and it also depend of a lot of things... ... . load... . HP... how far your foot is into it... etc.

 

[Allnew2Me]

My truck locks the TC at 35 and will hit OD anywhere above 40 depending on pedal position, temp, and load/speed.

 

[DCreed]

if tc lock is working your rpms will drop like an extra gear (at 60 ish) and if u press the fuel pedal lightly should feel like a stick rather than auto if not you have issues.

 

[Tractorat]

So here is what it does.

Pulling my trailer with tow/haul on (OD off)

1 to 2 (obvious drop in rpm, then back up as I accelerate) then a hard "bump" with no rpm drop, but seems like more power, then to 3rd (with drop in rpm, then back up as I accelerate)



So if I understand correctly, the "bump" is the tc going into lockup. And Im guessing then that it just stays in lockup when it shifts to 3rd ?

 

[LOtero]

the bump might be lockup but you should see an rpm drop.

a way to test the lockup is, when you think its locked tap the brake, your rpm should jump up a lil bit, meaning its unlocked. hitting the brake tells the trans to unlock the t/c.

 

[zstroken]

The bump is third, it is unlocked so that is why there isn't a RPM drop.

 

[Tractorat]

Thanks Zstroken,

So does that mean that what I thought was the shift into third (rpm drop, and then rpms coming back up as I accelerate), is lockup ?



TRat

 

[zstroken]

The hard bump with no RPM drop is 3rd gear with fluid coupling. If you would shift from gear to gear locked you should see RPM drops, unless your convertor is slipping, or something else.