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Over drive control

Hi I drive a very old 1993 Oldsmobile Achieva, which was discontiued due to it being a lemon of a car lol. But since I own one, I hve to endure its little quirks. I took it out on the highway and it started to loose speed somemtimes at a high speed and then stall out every time I slowed down. Went out of town so it scared me on the highway acting up. I have had two different mechanics look at it and they think it might be the overdrive control that is not working right. So they disconnected it and told me to drive it that way to see if it still does the same thing on the highway, Two different mechanics took my car home on the highway and the car did not act up so they think it must be the overdrove control. Both have told me it is safe to drive without replaceing this part, in order to save me money. Does anyone know what exactly the over drive control does and if it is safe to drive it disconnected on the highway?

It is perfectly safe to drive with the overdrive disengaged. Overdrive is a tall top gear that allows you to save gas and engine wear. There is no danger to disengaging the overdrive.

Agree; my wife always drives with the OD off on her Nissan; she likes the extra power in the third gear. Who am I to argue!

The 93 Achieva came with a 125C transmission. 3 speed no overdrive. What the mechanics are talking about is the TCC (Torque Converter Clutch) solenoid, not an overdrive control. Common problem with the 125C is faulty TCC solenoids. The connector for the solenoid is on the bellhousing of the transmission. You can disconnect it to see if the problem goes away but do not drive it very far with it disconnected. Driving W/O the converter clutch will cause the transmission to run hot which is not good for it. Have the solenoid replaced.


So the real problem is that the locking torque converter doesn’t unlock?

Yea, the solenoid sticks causing it to stall in gear when coming to a stop. He is also feeling the converter lock and unlock at highway speeds. This was a very common problem with the 125C’s.