Re: 1959-63 QD’s Opinions?

[Don]

quote Phil B:

A mid-1960 modification strengthened the lower unit:
The drive shaft and pinion are splined (instead of keyed), and I think the gears are heavier (fewer teeth).

You are correct indeed….But, no matter how many updates or improvements were made, the lower driveshaft pinion bushing and its mating surface on the driveshaft continued to be an issue, especially if water made its way into the gearcase.
It’s ironic to know these same gearcases were used on the 9.5hp models, too bad the driveshafts are shorter! All the issues we have talked about don’t seem to affect the 9.5s much, so I’m thinking the 10hp models surely had much more power than the 9.5s. Yeah, I know, this is not a new revelation, just me thinking out loud…