How to replace overdrive relay on 2002 alero - 2002 Oldsmobile Alero

I don't think there actually is a overdrive relay. It is likely a electronically controlled transmission so there are probably a couple of control solenoids. There are four possible combinations with two solenoids controlling hydraulic flow (1 off 2 off, 1 on 2 off, 1 off 2 on, 1 on 2 on) four forward gears can be operated by the drivetrain computer. There is also a lockup torque converter solenoid. Those can be mounted outside the transmission but a lot of the time they are just inside the drain pan.

There isn't an overdrive relay. There is an overdrive solenoid. It takes about four hours to replace. You better have manuals and patience to do it. otherwise you will mess up the transmission worse than it is already..I really don't recommend a nice to do it. When you take it apart, there are parts that fall out. You lose them or don't get them back in place, a transmission rebuild ,plus extra parts are in the works for you.