[rotorwrench]

The high gear is engaged with dogs on the end of the input shaft that engage with the intermediate gear. If the dog teeth have a lot of wear or the spline grooves are worn in the intermediate gear then that could allow for easier demesh of the 1:1 ratio drive. Straight cut gears generally don't have much of a thrust load either way but excessive gear/mainshaft end play or movement could be troublesome in this respect. Condition of the shift tower components could also have an affect. If a person takes the shift tower off the lower case then a visual inspection can be performed on this stuff to see what the condition of the gear train and shifter components are in. I'd look for wear on the bottom of the shift lever where it engages the shift forks. A lot of wear won't allow the intermediate gear to move as far as it should.