There's already 37,000 miles on the original fluid, and Subaru says to drain and refill IF it is on "severe duty", so I decided to drain and refill front and rear diff, having already drained and refilled x 4 the ATF with Valvoline synthetic ATF.
WalMart had ST gear oil on sale, but it was 75w140 synthetic, which is too heavy, 75w90 - which is the right weight, but only semi-synthetic. so i bought 4 q. of 140 synth, 3 q. of 90 semi synth(which was all they had) and FRANKENMIXED IT!!! with 3q. of Valvoline synthetic ATF, to thin it out to a 70w90 in order to get a fluid that should be 80% synthetic. Result:extremely smooth, easy rolling.
WalMart had ST gear oil on sale, but it was 75w140 synthetic, which is too heavy, 75w90 - which is the right weight, but only semi-synthetic. so i bought 4 q. of 140 synth, 3 q. of 90 semi synth(which was all they had) and FRANKENMIXED IT!!! with 3q. of Valvoline synthetic ATF, to thin it out to a 70w90 in order to get a fluid that should be 80% synthetic. Result:extremely smooth, easy rolling.
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