Low range on the planetary unit slides the sun gear in and out of engagement with the planet gears, and has a different area to engage the carrier assembly for high range. The high range engagement has a fairly small area of contact and is somewhat susceptible to wear from poor shifting habits, IE, getting back on the throttle too soon before it engages fully.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!