Odometer not working but all gears and shafts are turning
 

My odo doesn't work in my 83 944 so I ordered this gear hearing how common of an issue it was for them to break.

https://www.pelicanparts.com/More_In...YaApP1EALw_wcB

I pulled out the cluster and the odometer only to take a look in the back and find every single gear intact so I tested it manually and tracked all of the gears and found them rotating like normal (also the gear in my speedo was not the one linked above, it had fewer teeth). I even tested the shaft that goes through the normally broken gear and that was rotating as well. I threw it back in the dash and still no luck, it still doesn't work. Any ideas?

On my 83, the odo gear had slipped along the shaft and was no longer engaging the odometer. It was close, I mean really close but did not make contact enough to rotate the odo.

I will check but the odo shaft and gear are moving. I marked them and confirmed they were moving

+1 what GuyS said, the gears have a habit of moving along the shaft as they wear, try and see if any of the gears can slide sideways by pushing against them with a small screwdriver.

Also on the gear sizes, there are various types and they are not readily identifiable by year, that is why Pelican states:

“NOTE - We strongly advise you to confirm the correct tooth-count used for your odometer BEFORE ordering. Part numbers from any part of the speedometer do not help in determining the tooth count.”