What size are the drain and fill plugs on the diffy?

I bought Mobil 1 75w90 syn. is that ok?

 

10mm hex

Is that the synthetic GL-4 gear oil? Just make sure it's yellow metals compatable.

 

it's GL-5. will have to check on the YM compat.

 

GL-4 for 6mt, and GL-5 for Diff. I'm pretty sure 75w90 is fine, it probably says GL-5 somewhere on the bottle.

 

I did this just a week ago.
Yup, 10mm hex is the deal.
GL-5 for diff, GL-4 for tranny.
I did the Mobil 1 75-90 just like you for the diff.
I did the Amsoil GL-4 Synthetic for the tranny. If you're 6MT then you might want to think about doing that too while you have your car up and your pump all oily. It does get messy. but everything is ohhhh soooo smooth now!
Oh, and check out, and clean off, the drain plug on the diff. It is magantized, I have never seen so much creepy gunky crap on a magnatized plug before. I was real glad I did it!!

 

I have done mine twice in the last 6 months with redline 75W90 and both times the rear diff has tons of gunk on it. I can't believe they say to wait so long between changes!

 

That's why I change mine every 10K now..... costs me like $10 for oil only....labor is mine-free!!

 

I'm thinking about changing mine soon, and taking the opportunity to change to NISMO finned cover. Since you guys were up under the car, how difficult does it look to install? Pretty straight forward or look like a pain in the neck. I'm mechanically incline with good set of tools but no lift. Oh, and the torque spec for the cover if anybody got'em. Any comment is appreciated.

 

I didn't even use lift.

My garage has a 1-2" 'step' above the driveway, so I left the rear wheels right above the uneven part. That gave me the clearance.

It was simple: remove top fill plug on the passenger side, remove and drain fluid from lower plug. Then reinstall lower drain plug. I used a gear oil extension tube from walmart. it will take about 1.5 quarts. Just put on the extension and squeeze. When its full fluid will start to come back out of the fill plug. then you are done.

 

Has anybody used the old filler and drain pug gaskets for the diff. and the tranny? are all the same? are the gaskets available at the autozone or advance autoparts?

 

I want to replace the transmission and differential drain plugs. Does anyone know the size of the bolts?