Engine/Transmission (1998.5 - 2002) lock up mystery

[MCharlebois]

i put in a lock-up switch from the tst instructions... . i know it is working, from say 30 on lock it up and she pulls hard to 4th... . try to stop with lock-up on and truck wants to jump out of its skin... ..... however,if i slow down to 40 mph and punch it ,it will pull hard for 1-2 seconds and then shift down to 3rd,from what i gather it is not supposed to downshift??

i used 16 gauge wire ... have the toogle ground to the battery. i used a piece of 14-2 wire for the jumper because the 16 gauge was to small

something i missed?

opinions will be appreciated

thanks marcel

 

[DLausche]

Where are these TST instructions available? I've always wanted to do a lockup switch too. I know it is easy to make the converter stay locked, but how does one keep it from downshifting? Do the TST instructions address the downshifting also?



-Deon

 

[Nate]

http://www.tstproducts.com/Torque Converter Lockup Switch.pdf

 

[DLausche]

Thanks Nate! That looks quite easy to do.



-Deon

 

[Cummins Thunder]

At 40mph it should be gettin close to hitting third at wot.

Are you saying it downshifts and tachs up to about 3500rpm and stays there?

Your question is kind of confusing...



BTW, don't try and stop the truck while in LU

 

[MCharlebois]

cummins thunder,

what i am saying is if i l et the truck shift up into overdrive ,then slow to 40 mph,hit the lockup switch and nail it . . truck stays in overdrive for a few seconds then shifts down to 3rd... and tacks out again befor shifting back to overdrive... ... . this is a no. no on the dyno from what the owner said,because with an auto how am i supposed to get the true dyno numbers if i can`t floor it and let the torque do its job ... ... i need to be able to mash the pedal and not have it downshift,that`s all. next question, if i have a lockup switch , can i dyno from say 30 mph as long as the shifts are locked??

thanks marcel

 

[CumminsAholic]

You probably could if your turbo would spool. I know I wish they would have started lower when I ran mine. The second run I made 60 more ft lbs, they started about 200 rpm lower. It'd help if I had a drag comp too, so it didn't defuel. I don't know if it's supposed to stay in overdrive, I thought it was just supposed to keep the converter locked up?

Corey