Dont do that, on a GSR 5th gear is higher than others so with that being said its the last one to get oil, low levels of oil can cause you big bucks.

1. Level the car on th ground, NO DONT HAVE TO USE A LEVEL
2. Fill until oil starts gushing out the fill hole, this should be aprox 2.8 quarts

 

Yea man fill it untill it comes out 2.5,.6,.7,.8 whatever it is. stick the fill bolt back in and be done.

It's not a new concept. It's a manual tranny 90% are drained and filled the exact same way

 

alright i was just concerned that the owneres manuel said 3.0qts and not 2.5,.6,.7,.8 and i get about 50/50 on answers to put exactly 3.0qts and others to fill till it comes out.
like i said before ile just put it in til it comes out nexttime and just cross my fingers

 

No worries you'll be fine. No need to cross your fingers. Don't be paranoid it's only a car.

You can force the 3 in there. It won't hurt but It's gonna **** at ya just put the bolt in while is pissing out and tighten it up. Grab a and relax

 

^sounds like he needs 2! There ya go, OP! Like gsr said, it is an old concept and the majority of them are done this way. BTW - your rear diff and t-case fill the same way but with different fluid and volumes!