Home › Forum › Ask A Member › 1957 Mark 30 lower unit setup › Re: 1957 Mark 30 lower unit setup
It’s been quite awhile since I had one apart but I don’t remember any shims between the ball bearing and reverse gear. This would be the 15-20822 you’re talking about. Even if you bought some, shimming between the ball bearing and reverse gear would only make your problem worse, moving the reverse gear CLOSER to the pinion gear. You want to be moving the reverse gear backward and away from the pinion gear. This would be accomplished by the 15-24592 shims, reference number 17, in the drawing. The general rule is that when you have no idea what amount of shims you will need, start with a total of 0.015", then start checking the clearances and making any adjustments as needed.
Long live American manufacturing!