[navanodd]

Originally Posted by Gforce

This is pretty interesting. Japanese corporate brochure but with English.

http://eb-cat.ds-navi.co.jp/enu/jtek...catd1001je.pdf

Apparently the friction involved in torque biasing of helical differentials is axial against the bore.

Makes sense, helical cut gears can generate a lot of axial force.

The primary reason that racing gearboxes use straight cut gears is so that stronger, heavy transmission casings are not required to hold the axial load.