Torque convertor locking/unlocking while cruising

[RambleOn]

On my way to and from work when I'm driving my 92 Buick Century 3.3 V6 3 speed auto I drive on a road where the speed limit is 45mph. When I'm cruising along between 40-45mph, this particular speed causes my torque convertor to lock and unlock while cruising when I'm adjusting pressure on the gas to hold speed. Is this shortening the life of my tranny/TC?

 

[killmeplease]

Not good for it. You could have the modulator adjusted to fit your needs a bit better (at least most models of that era can).

 

[Tominator]

Although all modern locking torque converters are controlled electronically, I'm not familar with your model. I'd buy a Chilton's or Haynes manual from Autozone for your car. For less than $15 you have a good reference manual even if you do not plan on doung your own repairs.

I'd think your problem should be fairly inexpensive to fix. If it were me, I'd take it to a reputable transmission shop and have a complete 'tuneup' on the tranny includeing band adjustment and fluid and filter along with fixing your problem. They should give you a free estimate.

 

[yellowvespa]

Torque converter lockup is controled by the computer. Adjusting the modulator (modulators adjust shift points not lockup and besides, you may not even have one!) or getting a trans service will not help. You are driving in that fine MPH area where the computer sees all the right parameters to lock it up and unlock it like crazy. What I did to cure this is below.

Some basics: When the computer sees a certain MPH (different on all models/engines), throttle angle, etc. it will lock the converter up for better gas mileage. The wiring comes from the solinoid in the transmission and goes to a switch on the brake pedal (to disconnect the lockup as soon as the pedal is touched), and then on to the computer to be grounded. The lead is 12v, the computer provides the ground. What I did on my GM car (since they didn't provide a lockup on/off switch) was to splice into (cut) the lead at the brake pedal and come up to a toggle switch I mounted on the dash. I can now cruise around town without the headaches you are having ( I had them also) and turn the lockup on when getting on the highway as needed.

Note: the lockup on/off that you are experiencing is normal and no dealer or tech can adjust it without replacing the computer prom (chip) which is where the lockup parameters are stored for your cars functions. The car is just doing what it is suppose to.

good luck