The Stovebolt Site Forums The Shop Area Engine Shop Lock-up vs. Non-lock-up

What is the differance between lock up and non lock up on a 700R4? I know it has to with computer controlled and locking up the torque converter, but what dose that do?Thanks! :confused:

Mallard It is just as it says .You lock the converter up in high gear there is NO slippage.You get better gas milage,less heat build up(slipping converter build heat)Its also can be done without a computer with a kit from TPI .We use them all the time in rods.The thing with a lockup is it has to disengage as you slow down or when you come to a stop the tranny will kill the motor till you unlock the converter.They use a pressure switch on the side of the tranny wired to a valve inside that disengages the converter when the pressure starts to build(like when you step on the brakes)

Thanks Phat!! I have seen the kits just wasnt clear on how it all worked and what it did. Now Iam. I have been "dreaming" about the TCI Streetfighter. Later!

Running a 700R4 without the lockup will cause a premature failure of the trans due to excessive heat buildup. Ask most trans builders and they'll tell you that if you don't plan to use a lockup, they won't warrantee the trans. It isn't that hard to add, and it'll give you 1-2 mpg improvement.