Hi I'm wondering how I can lock an automatic transmission in my late father in laws 2004 pontiac sunfire as one would do with a manual transmission. We know that locking a manual is just welding a couple of the spider gears but on an auto, we aren't sure on how this could be done, the engine is a 2.2 eco if that helps any. But any ideas or anything would be appreciated as this was something he wanted done before he passed thank you in advance
You can electrically lock a gear as well as a TCC. Just curious why? You could always see if there is a manual valve body for it.
Sounds like he talking about locking the diff, not the trans.
Nothing to do with the dif, we lock the manuals from within the gears of the transmission its self
We lock the transmission in order maintain our rpms when we are cornering. Locking the trans helps keep the rpms up as other with out a locked trany will dip in rpms. So say you are coming into say turn 3 and 4 on a dirt oval, locked transmissions will let you stay within 3rd gear with little to rpm loss as with a normal transmission youbare forced to drop a gear to maintain those rpms. Easier point it helps with letting you fly around the corners faster
I didn’t know that transmission had actual spider gears.
What part of a manual transmission slips to let Rpm’s drop?
The transmission doesn't slip its the fact that when you slamming the car into the corner, you put all the weight on the right side of the car and you lose speed and rpms. When we lock the transmission it keeps us within the power band on the rpms to carry us through the corners whit out dropping
I'm sorry but that makes no sense. The only thing I can think of is keeping the torque converter UN locked. That would keep it up in stall/RPM even though actual speed is reduced.Originally Posted by Jordon99
Still sounds like doing something to the diff, which is in the transmission on a front wheel drive vehicle. We are talking about a front wheel drive?
Yeah, your talking about welding the diff. We do it in all our circle track dirt cars. I have done autos with the tranny in the car by hole sawing a 2" hole in the case.
You have to wire it in on a switch. The TCC signal comes from the transmission and the ECM grounds the solenoid using PWM to vary the clutch pressure. If you put a switch on the dash that grounds that wire it'll lock the converter and leave it locked until you turn the switch off. Done it many times on customer's cars. Makes a big difference on lap times and transmission temps at the end of the race. Still not as fast as a manual but close. At your ECM find the brown wire on pin 12 of the black connector, clip it off and route it into the cockpit, hook it to a toggle switch and on the other pin of the toggle run a wire to ground. When he's on the track flip the switch and the converter will lock and stay locked. Unfortunately there's no way to do it in the tune because no matter what when you go wide open it will unlock and if you trail brake in the corner it will unlock. With the switch you have direct control of the converter. Good luck!
Do you have a wiring diagram of this procedure
Reply With Quote