[gg1978]

I was going through and filing my brz's maintenance paperwork today and while reviewing it, I noticed that the gear oil used for both the manual gearbox and rear differential was listed as the same item, quantity 3 for trans and 1 for the diff. The description is listed as Valvoline 75W90 synthetic.

From what I understand the torsen rear diff likes 75w90 LS type fluid while the trans is gl3 or gl4 but without the LS as that type of gear oil has sulphur which can corrode the synchros in thr long term.

I did a google search for valvoline 75w90 synthetic, which at first view seems to be a LS type oil that is compatible with GL4, but upon further review of the product info for it indicates that valvoline doesn't recommend it for any transmission with synchros, so nothing made in the past 60 years or so.

Is there another 75w90 that they may have used that might not be LS type, but then I would have to get the diff changed to LS type, or is the more likely conclusion is that the trans has LS type in it?

I have put in an initial call to the dealership about this but was just wondering what gear oils the dealership has put into other ft86 type cars.


Thanks!!