Second gear seems to be weaksauce. Will 2nd gear pop just under normal HP duress, or are people blowing these out when they slam second?
I’m glad someone asked this early. The popular Synchromesh/hypoid C combination is exactly the wrong fluid for Subaru’s. Synchromesh and Hypoid C are both GL-4 fluids. Subaru explicitly requires GL-5 fluid. But, upon disassembly, there’s not any specific damage visible to the gears or synchros or bearings. From my experience, the reason the popular cocktail helps shifting is not due to the synchromesh and hypoid C, but entirely from the Shockproof. We use some variation on a combination of Redline’s Lightweight Shockproof and MOTUL Gear 300 75W90. Usually a 50/50 mix of Smurfblood/Motul works well. If you notice shifting to be particularly grindy, a 75/25 mix can be used. I’ve got 167,000 miles, and run 100% Smurfblood and it shifts fine. No fluid will make the gears stronger though. Keep that in mind. After Querying Redline, the only reason I can determine that Smurfblood is not “for synchronized transmissions” is because API Certification costs a healthy packet, so saying it’s not fo