Many questions are always asked about what features and characteristics of the overdrive are normal or not. Problems always arise since people will compare the operation of different years and think something is wrong. This chart was designed to help you see these variations. There were also changes in the amount of side cover switches on the 4 speed section. All 1984 cars had 3 switches (1st, 2nd, and 4th ). 1985 , 1987, and 1988 cars had a 1st gear switch and 1986 cars had NONE.
No overdrive ever Accelerating at >20% throttle turns OD off until 4th gear |
Overdrive after downshifting while OD is engaged No overdrive upshift OD kicks out on acceleration Accelerating at 8-38% throttle turns on 2 second delay |
Overdrive after downshifting while OD is engaged OD may be engaged with button OD kicks out on acceleration, if RPM <4000 Accelerating at >60% throttle turns off overdrive in all gears |
Overdrive after downshifting while OD is engaged OD may be engaged with button OD kicks out on acceleration, if RPM <3000 Accelerating at >60% throttle turns off overdrive until 4th gear. | |
OD kicks out at 60% throttle OD kicks out at 55mph when accelerating OD stays engaged after downshifts if <20% throttle No automatic upshift after kick down |
OD kicks down at 75% throttle if RPM <2300 Button commands upshift if in direct No automatic upshift after kick down |
OD kicks down at 75% throttle if RPM <2500 Button commands upshift if in direct No automatic upshift after kick down | ||
OD kicks out at 60% throttle OD kicks out at 60mph when accelerating OD stays engaged after downshifts if <20% throttle No automatic upshift after kick down |
OD kicks down at 75% throttle if RPM <2300 Button commands upshift if in direct No automatic upshift after kick down |
OD kicks down at 75% throttle if RPM <2500 Button commands upshift if in direct No automatic upshift after kick down | ||
OD kicks down at 60% throttle Automatically upshifts after kick down with no delay |
OD kicks down at 80% throttle Automatically upshifts after kick down after 2 seconds at <80% throttle Auto OD upshift at 110 mph |
OD kicks down at 75% throttle if RPM <2300 Automatically upshifts after kick down with no delay Button commands upshift if in direct Auto OD upshift at 103mph |
OD kicks down at 75% throttle if RPM <2500 Automatically upshifts after kick down with no delay Button commands upshift if in direct Auto OD upshift at 103mph | |
On / Off switch Opens OD circuit No RPM limit on downshifts |
On / Off switch Input to ECM No downshifts over 3500 RPM |
Momentary contact switch Input to ECM No downshifts over 4000 RPM Turns program On/Off Program ON when starting Switching ON commands upshift in any gear and/or turns program on. |
Momentary contact switch Input to ECM No downshifts over 4100 RPM Turns program On/Off Program ON when starting Switching ON commands upshift in any gear and/or turns program on. |