Thank Rhyd & 540964,

Okay so just gently pull straight up this is contrary to the article in Pelican where you have turn it clockwise etc...

 

any dust left on the black face will glow when lights are on so be sure its clean.

 

I have 90 964 C4 Cab.
I have the same problem as Jimq; after replacing the small gear 8 years ago, now I need the larger reddish gear, the one you see in Jimq picture.
I guess it's 17 tooth.
So do I need to call odometer gear to find out which gear I should get? Do anybody know the part# may-be?

 

Odometer gear guy (Darren) helped me out.
I ordered 17 tooth small pod here:
https://www.odometergears.com/products/Porsche/911-964+89-93+%28Non-US%29/71

 

Seems that these odometer issues are epidemic, had mine at 30k in 2014.... had my small gear go out and may have lost some 600 miles. Amazing how easy it is to go without checking the odometer....not something you look at all the time until you get around to changing oil and then discovering that sine the last oil change you have driven so few miles. I obtained the right two gears did the DIY and replaced both gears...rechecked the distant traveled metered by the various State mileage markers....also made sure to note it in the maintenance manual for all to see if ever I sold the car....No doubt if they were an informed 964 prospective buyer they would ask that question....or should ask that question. Initially for some reason the trip odometer did not work but it seemed to fix itself.