Brad,

What year three speed?

Which gear are you referring to: the drive gear or the driven gear?
It looks like you are referring to the driven gear.

The driven gear is the gear that the speedometer cable goes into. The drive gear is on the main output shaft inside the transmission. (if I am wrong, we will quickly hear about it)

Both of those gears are metal in my 54 transmissions.

Here is a photo of the gears - wrong transmission, but the locations and general appearances of the two gears should be similar to yours.

Maybe you are referring to a plastic gear/part inside the speedometer unit on the dash? (sorry about my poor comprehension)

Tim
1954Advance-Design.com
1954 3106 Carryall Suburban
1954 3104 5-window pickup w/Hydra-Matic
The 216 and early 235 engines are not "splash oilers" -- this is a splash oiler.