speed-o-meter gear

[30ratrodder]

Hi All
I have a closed drive shaft for a 1940 rear-end. I'm looking to find a new gear for the speed-o-meter. I don't know how you would call it but it is for the little aluminum part that is on the tube.
Thanks

 

[super flat]

speedometer drive unit. be aware there are different tooth counts for the tire sizes and gear ratio. Gary

 

[Nirvana]

what number do you have on the turtle now?

 

[Bassman/NZ]

It's called a turtle and with standard rear 3.78 gears it has 19 teeth. A 3.54 rear will have 18 teeth, 4.11 will have 21 teeth.