Engine/Transmission (1994 - 1998) Is there any way

[champspa]

Is there any way of keeping the torque converter from locking up in overdrive ?

 

[Hummin Cummins]

Mystery switch

I have read of guys using the "mystery switch". I believe it is a three position toggle switch. One position is full lock, one is normal operation, and one is unlock.



I used a floor headlight dimmer switch from a ford pick up. Cost about $5. It breaks the ground for the t/c. I run it unlocked then when I reach the right conditions/speed, a simple tap of the toe and you have lock-up. The TST site has the instructions for the mystery switch. Just loop the proper wire into the cab through the switch. I think it is the orange/black wire on the pcm, but better check the instructions first.



Chris

 

[shendren]

ground the orange wire with the black stripe going to the trans.

 

[Dennis Garrett]

Here's a photo of my switch location, it's a 3-pos switch, "center off". Pulled all the way back it's stock, in the center the TC is unlocked, or if driving in lock up, moving it back to center unlocks it. Flipped full forward, locks the TC, and it will not unlock until moved back to the center or stock position. If I remember correctly, the orange & black wire is cut. One end attatches to the center of the switch, & the other end of the wire goes to either end of the switch, the remaining end terminal on the switch is grounded. Mine's a 97, and the instructions I had at the time, said to remove the transmission relay on the fuse box, and replace it with jumper. I put the switch in mine when I first got it, and drive it 100% of the time utilizing the switch. I always start off in the center "Off" position, only locking up when I feel it's time. I don't unlock until I get down to about 1,000 RPM, getting a little engine braking out of it. If for some reason my wife or son have to use it, they know to put it in the "stock" position & leave it there when they use it. My brakes seem to last forever, and I got 160k out of my TC, before it started slipping. See signature for what I replaced it with.

#ad

 

[champspa]

thanks for your input guys , I'll give it a try

 

[redramnc]

Running unlocked while pulling creates alot of heat in the fluid because it is a viscous coupling instead of a mechanical lockup. If you don't have a trans gauge you might not know it is getting too hot until its too late. The OD Off button still allows the trans to lockup in 3rd but keeps it out of the weak OD gears. 3rd locked will let tow at 65 all day long without boiling the trans fluid. Just be careful how you use the switch.