94 Lumina shudders in between 3rd and 4th

[chey23456]

Hi everyone. I'm new to the list. My 94 Lumina is shuddering back and forth between 3rd and 4th gear when it gets warm. It also feels as if it's not slowing down like it normally would when you try to stop. It's as if you have to push down on the brake a little harder than you normally would to get it to stop. (It's as if something is behind it trying to push it) Does anyone know if this is a transmission problem or if it's something else? I read the other post on shuddering but I wasn't sure if this was the same thing or not and I'd rather not have to have the transmission work if it's not needed. Thanks.
If any of you received this as a private message instead of the board I'm sorry. I couldn't figure out how to post the message.

[jeffcoslacker]

It's possible the torque convertor lockup is starting to go bad. They will shudder sometimes, intead of going solidly into lockup, this will usually occur on even roads at about 40-45 mph. The lockup will rapidly cycle in and out. Can feel like it's hunting for a gear, if you aren't familiar with the sensation. You can disconnect the lockup solenoid temporarily to see if you can rule it in or out. It's just a matter of unplugging it. If you want to try, I will try to send you a picture of the location of the plug. Anyway, that would make sense, because if it is having a hard time engaging, it is probably having a hard time disengaging too. When they get stuck completely, as you stop it doesn't disengage the motor, feels like as if you were driving a stick shift and forgot to push the clutch in when you stopped. If it's hanging up, that's probably what you feel when you're braking. Don't let it continue undiagnosed, as it can lead to a disabled car and serious tranny damage.

[chey23456]

Thank you for replying. If possible I would like a picture of it. If you can't will you please try to explain to me in detail where the lockup selenoid is so that I can try to unhook it? Thanks. Jerri

[chey23456]

I forgot to ask one thing. Once I unhook this can I leave it like that or does something need to be fixed? Thanks. Jerri

[jeffcoslacker]

O.K. here is the deal. The lockup provides a solid (no slip) union between motor and tranny once the car is cruising under light load. That allows them to get better gas mileage. When you disconnect the TCC, as it's called, you will probably not notice any difference when you drive, other than gas mileage for that type of driving (sustained high gear over 40 mph) will drop, probably by 2-3 mpg. Also, the check engine light is gonna set a code and remain on with it disconnected. If you can live with all that, you can drive it like that. If that is the problem, since you have caught it early, it should only be a matter of replacing the TCC solenoid, you will have to consult a trans shop for a price. I am not able to mess with pictures right now, I gotta get going to work, but can do it later. If you open the hood, look at the trans case, to the right of the engine. Facing the radiator on the trans will be a (this is from memory, I'll verify on mine later) 4-wire, square plug going directly into the front of the case. You just unplug it, be careful not to break the connector, and drive and see if that was the problem. You can also look in your owner's manual, one fuse will usually say "TCC" or "Lockup", if so, and there is nothing else critical running on that circuit, you can disable it that way, too. Remember, it is going to set the "Check engine" light while disconnected. Don't let that bother you, it is supposed to happen.