I thought someone could use this info: Here is how I repaired the set-the-time function on the clock in my 1987 740 GLE. Pull instrument cluster. Remove many screws so cluster splits, leaving instruments available. Remove fuel gauge, then clock at obvious points. Remove clock hands by lifting with fingernails. Remove clock face by using thin knife blade to unstick face from behind (sticky pads are holding face on). Shake clock and listen for a little gear rattle in there. If it is white in color and hat shaped then proceed, otherwise you are on your own. Open clock housing by removing obvious screws or bolts. Retrieve hat gear. It was once spinning on a clear plastic axle but that axle is probably lodged in the gear. Tap it out or use a teensy drill bit to get it to slide out. That little clear pin has broken off the housing. So, find a finishing nail (or paper clip) with the same diameter and make a new pin. I used a 1 x 17 brad. I drilled a hole from the inside of the housing so that I could position the nail in the hole, thereby fashioning a new pin for the hat gear. I used a too-small (maybe 1/32) bit and then followed with a cut off finishing nail to bore a hole appropriate to the nail's diameter. I fed the brad in from the back of the clock housing until the head of the brad hit the back of the clock housing. Then I snipped the brad to an appropriate length so that it secured the hat gear as the gear was place properly between the two black gears that convey your setting motion (twisting the stem) to the clock mechanism. I then ground the head of the brad flat enough that the dial face (the clock numbers) could be positioned properly on the clock. I repaired two clocks this way. I would think you could bench test this by supplying 12 volts to the clock, as I got a 12 volt reading off my cluster where the clock connects to the board.