Wondering what the function of the lockup is for and if you disconnect it will ones tranny still function right.

 

The torque converter has a clutch in it to lock the converter to the input shaft and eliminate all slippage. There are two reasons for this, one is to improve gas mileage slightly, the other is to prevent overheating while cruising in 4th.

 

He's right, it eliminates slippage and keeps the tranny from nuking itself. Oh yeah, if you care for your transmission at all, make sure you have a cooler to go with it

One question though - is lockup on every gear or just 4th??

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1980 Camaro, '88 Police 350 engine, Headers, full exhaust, completely redone, my baby!
1988 Iroc-Z L98, MSD 6a, Accel coil, K+N's, Airfoil, Coolant Bypass, Flowmaster, Gears, Late model Bose, I like the 80 better

 

It can lock in 2nd, 3rd, and 4th. Even with a switch, it's not possible to lock-up in 1st gear. Torque converters kill efficiency because they slip, which creates heat. The heat is lost energy that could have gone to the rear wheels.

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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro

 

I remember seeing a TSB from GM that said to avoid overheating, the TCC clutch must be used when cruising in 4th gear, and must NOT be used when cruising in 2nd gear. I'd have to go dig it up to remember the details.

In most computer-controlled thirdgens, the TCC should lock up part-way through third, and stay locked up in 4th.

[This message has been edited by Apeiron (edited March 02, 2001).]

 

every stock 3rd gen i have been around in cluding mine (till i installed a switch to my brake pedal) the converter locks in 2nd gear and lugs the motor and sounds like crap,unless you get on it a little and then it will unlock in 2nd. i think that even at WOT the convrter locks in 3rd.

 

Found it, this is from TSB 89-21 (July):

POINTS TO REMEMBER ABOUT LOCK-UP SPEED:

1. If we have lock-up in 2nd gear, the transmission will run hot because the planets are in reduction, and cooler flow is reduced (orificed) in lock-up.

2. If we delay lock-up too much we could be operating in fourth gear without lock-up, which will severely over-heat the converter and burn up the transmission. (which is why we can't use the 8642970)

3. Lock-up should happen while in third gear -- probably half-way between the 2-3 and 3-4 shifts.