FAST GE WASHER TIMER
Sorry I did not see this and respond earlier. Your timer is one speed only, you likely have a bad or the wrong timer motor or maybe the complete timer should be replaced. Keep looking it is out there somewhere. GE never used the two speed timer feature in the 1980s and never with the quick disconnect timers like this machine has that GE did not build. The two speed timers were used on late 1960s machines through much of the 1970s on very high end models only, and it was always on machines that had the GE built all black plastic bodied timers.
Did you see what voltage, cycles and maybe timer motor speed is listed on the timer motor it self? This might help us see if the motor is the wrong one. If you can even find another GE washer or even a new or used timer for the same, you may be able to just switch the timer motor to your timer, many timer motors are interchangeable within certain time periods.