Re: Push Button Auto L and D have disappeared

Posted by Ross On 2024/6/3 7:08:16

A little more info is necessary: Is the problem that the shifter isn't shifting--that is that the shifter motor is not doing anything when you select those buttons--or is it that the transmission is not doing anything when you press those buttons?

You can check for the first problem by listening carefully as you press the buttons with the engine switched off but the ignition on. You can tell by the sound and by the brief slight dimming of the courtesy lights that the motor is working or not. If not working, I suggest that the contacts inside the shifter gearbox have failed if all other positions work normally.

If the motor is operating and you are just not getting the gears that you want then there are two very likely culprits. The first and easiest is that the setscrew that attaches the PB unit to the transmission is loose and you are a victim of lost motion. The second and much more likely cause is that the shift lever inside the trans that operates the valve body has come loose on its shaft and you are again a victim of lost motion. Then you must drop the pan and tighten that set screw. Afterwards, drill clean through the lever base and the shifter shaft and install a tight fitting roll pin, or spring pin.

My first boss after college taught me that one never secures an oscillating load with a set screw. He was right. John Delorean did not have the benefit that wisdom.