Im about to buy some gear lube for my Integra and was wondering if the Amsoil synthetic lube in 80W-90 would be too thick, also how much does the tranny hold?

 

well if the acura manual says you can use 10W30, I'm guessing that 80W90 is way too thick. MTF is thin just like 5W30 or 10W30.

 

Get RedLine MTF or Honda MTF. If neither of those are available, just go 10w30. Not sure if they make gear oil that would be suitable, but if they did it would probably be more expensive than 2.6L of oil. (I think its 2.6 anyway...)

 

so gear lube is basically just motor oil? in a manual tranny how would thicker oil affect trans function?

 

The 10w-30 or 80w-90 numbers just tell you the viscosity. There's all kinds of other properties; lots of them are given by specifications like API-GL4 or SJ or SL or ACEA something or other.

The bearings & clearances of your transmission can be designed to work with either 80w-90 gear oil or with 10w-30 motor oil.

Synchros are kind of like little wet-clutches. They have to get the gears spinning at matching speeds so they can engage. If the oil is too "slippery" then they don't work so good. That's why some manual transmissions don't like synthetic oil. Lots of trannys these days are designed to take thinner engine oil, so they can take advantage of the fact that it doesn't turn to molasses when its cold.