BorgWarner Overdrive Transmission

[49-P15]

I'm overhauling a BorgWarner Overdrive Trans for my 1949 Plymouth.  the present conundrum concerns the gear that drives the speedometer.  Not the little spindle that drives the speedometer cable, but the cylindrical worm gear that sleeves over the transmission output shaft and drives the spindle.  I expected a key or pin to hold this gear in place and make it rotate in unison with the output shaft.  But there is nothing.  And the gear rotates freely on the shaft.  

     Maybe it was originally a pressfit (but it no longer is).   Am I missing something?  Or is there a solution to attaching the gear to the output shaft.  

[Bloo]

How does your driveshaft attach? Is there a flange on the output shaft? If so, what holds the flange on?

[m-mman]

What he said.

Hudson transmissions have the speedometer DRIVE gear spin freely on the output shaft until the yoke is slid in the rear of the trans and tightened to the output shaft with a big nut. After that it is pinched into place and no longer spins. 

[49-P15]

The output shaft is splined.  Picture attached.

 

 

[Bloo]

Ok, but what goes on the spline? I'm betting that isn't a sliding spline like a newer (post-1965) Mopar, because I see threads out past the spline. I'll bet when you put on whatever piece goes on that spline, and tighten it up, it will clamp that gear solid.

[c49er]

That speedo drive gear is held firmly in place once the emergency brake drum/hub assembly is installed and the1-1/16" nut is torqued to spec...simple.