Trying to fix bouncing speedometer needle

[habs]

I am attempting to repair the speedometer from my 87 924S. The needle bounces and clicks constantly, at all speeds. None of the plastic gears have obvious signs of wear or damaged teeth. I think the problem is with the first plastic gear, where the screwdriver is pointing in the picture. When I manually turn the speedo, I get resistance in the same spot with each revolution of this gear. I sprayed a bunch of silicone lubricant in there and cleaned as best I can with a pipe cleaner. Unfortunately the resistance/sticking problem is still there.

Does anyone have any advice on what to try next? Can the shaft that's attached to the gear be removed without damaging it?

Thanks in advance!

[originalowner]

Does this still have a cable driven speedo? If so, I would lubricate the cable.

Edit: Sorry, didn't look at the picture. Lubricate your cable.

[16again2009]

I had the same problem. I could not find a replacement for that gear so I bought a used speedometer.

[924RACR]

+1 for lubricate the cable.

[habs]

Thanks guys. Unfortunately I don’t think cable lubrication is the problem. I’ve already put in a new speedo cable (and lubed it a second time) with no obvious change to my bouncing needle. This led me to suspect one of the gears may be damaged. Looking more closely at the teeth on the first gear, each one has a small concave notch (slightly visible in the previous picture). I can’t tell if these are intentional, or from normal wear after 140K miles.