95 240sx - Manual Transmission Gear Oil

[mclaugbj]

Good day. I was wondering if someone could provide me some info in regards to how to change the transmission gear oil? Can I use Mobil 1 synthetic 75W90? Thanks!

[cleopp3]

Hey check out 240sxtech.com, Has info on how to change the gear oil and what not. Ive had mobil 1 75w90 for a while now in my transmission, seems to be working fine. Ive also heard that redline mt90 is also very good as well.

[navysnail]

its really easy, there is a side fill hole and a bottom drain hole. open both to drain, close bottom one, open side to fill with a fluid pump if you have one. MT90 is probably the best, but any 75w-90 will work. nissan recomends a non synthetic, because synthetics are too slick, and will interfere with the synchromesh mechanism

[mclaugbj]

Thank you very much. I appredciate it man.

[pjherring]

I use a cheap brand of 80w90 Works great

[480sx]

FFS dont post things you dont know about, you can really screw people. If you use any old 75-90 in a nissan transmission with its yellow metal syncros you will destroy them and have a very expensive problem on your hands.

You HAVE to use gl-4 approved fluid or you will destroy your syncros over time. GL 4 isnt that common and usualy comes in the form of GL 5 + GL 4 approved. I use AMSOIL GL-4. Read the lables on the back to find out, its all right there.

[cleopp3]

My question is if Ive had the gear oil in there (75w90) exceeds gl-5 ratings, for aproximitley 2k If I replace it now with either mt90 or a gl-4 fluid will it increase the damage occuring since its non-synthetic?

[navysnail]

no. if you have gl-5, the best thing to do is go ahead and drain it, replace with gl-4 or equivalent (MTL, MT-90, etc...)