[McLaren-TAG]

I have a variation that after reading through this entire thread, couldn't find and answer. My issue is with the odometer on an 86 coupe. The odometer does work, but it takes a few miles of driving for it to begin working. It starts out not moving at all, in a few miles it begins counting up at a rate of about 30% actual mileage, and within 10 or 15 minutes of driving it's back up to 100% accuracy in mileage. The speedometer works without issue.

So my question is, since the odometer does work eventually, the issue seems to me that something (the gear) is slipping and only when it warms up, it expands enough to firmly grasp the shaft and begin to turn properly.

So before I delve into the repair, any suggestions on who I find the actual gear that I'll need so I can purchase it ahead of time and if indeed my gear is not broken but slipping, can I simply try a drop of glue on the shaft? Any other suggestions welcomed.