gear oil weight

[moparkid]

Hello y'all. Once again I come with cup in hand. Doing my first oil and gear lube change. Best stuff I can find at Auto Zone or O'Reillys is SAE 85W-90. Manual calls for SAE 90, but it doesnt say "W" 90...My question. Is the 85W-90 the right stuff? A dude at the store says he's been using standard 10W-40 motor oil for years as gear lube and swears by it. Confused. Help me!

[MotoRandy123]

Most of the Kymco's just say 90w. In reality 90w is 40w strange but true. Though the stuff labeled 90w
is a gear lube and not motor oil so the additives are different (more high pressure slippery stuff). I'd say
 anything with a 90 on it is OK and synthetic is a little better.

[Vivo]

Most gear oils are SAE90, 80w/90...  Any will do, except motor oils...