Re: 68 20hp Johnson Replacement Gears

[Anonymous]

The 18/20/25 HP lineage "5 bolt" lower unit existed for a long time, it shouldn’t be hard to pick up a complete, used gearset if there is a possible issue with compatibility. 10HP engines before 1958 used the "5 bolt" gearcase, so that may be an additional source of parts.

I seem to recall hearing (thru the grapevine no doubt) that they were machined as a set, and it’s better not to mix and match, but I’m sure lots of us do it (I know I have!) without tragic results.

I don’t know much about "5 bolt" gearcase evolution, I know in the later 10HP "4 bolt" gearcase they switched from keyed to splined driveshaft and fewer, heavier teeth in mid 1960 (I think).