i know the 5spd is picky but what is the best choice for 6spd gear oil? and what is dino?
thanks!

 

99.9% of the time what's best is what the manufacturer says to use,especially if the car is still under warranty and/or you're not having any difficulty. Dino= dinosaur ,as in 'fossil fuel' as in black gold. It's your regular petroleum based oil rather than synthetic.

 

well, I just did the trans oil change and settled on Mobil 1 synth.

1.) I wrote an email to SOA and got back the response that synth or dino oil will do.

2.) I called different Subaru dealers and I got back the answer that it was either Synth or dino.

3.) I went to Pep boys, Kragen, and walmart and only found Synth.

Therefore, I just went with the Mobil 1 because at that time, I just wanted to change the oil out since it was getting old.

 

I'm not sure that factory oil is synthetic but whatever it is I think it gets the job done. The 30k service on my car was done with regular 75w90 gear oil at a subaru dealer, and by 55k miles I was starting to get a very intermittent grind trying to get the car into 1st gear from a stop. I changed the oil with that factory fill stuff and i haven't had a grind for the last 15k miles. I'm about the change the gear oil again, and I'll be buying another drum for sure. It is a pain to get but well worth it I think

 

I would go with the recommended gear oil in the owner's manual. Redline recommends the 75w90NS in the transmission and a 75w90 in the rear diff. They could not verify whether or not their rear-diff 75w90 was GL-5 rated though. Because of this, I am using the Redline in teh Transmission and Motul in the rear-diff.

*This leaves me with an extra case of Redline 75w90 for sale.

 

what does the ns stand for in 75w90NS? and does the sti have lsd in the rear diff?

 

I would recommend a "search" on NASIOC with your diff question. I dont have your answer.

75W90 NS

This GL-5-type geal oil doesn't contain the friction modifiers for limited-slip hypoid differentials. This makes the transmission synchronizers come to equal speeds more quickly, allowing faster shifting and much easier low-temperature shifting. Can also be used in racing limited-slip differentials where weak spring design causes too much wheel spin.

75W90

Our most popular gear oil, this is the preferred product in nearly all car and light truck differentials, both conventional and limited-slip. 75W90 is preferred for most racing applications. It contains friction modifier which is recommended for limited-slip units. 75W90 Gear Oil can be used in many transmissions and transaxles; however, other Red Line lubricants have better frictional properties for rapid synchronization. Exceeds API GL-5.

*Hah, look at that. I answered my own question while answering yours. I'm using my case of 75w90. yay*

 

^ That is reassuring to hear. I've got all my crush rings and gear oil poised for install. I cannot wait.