2.5GT6MT

Thank you all. I am just waiting for some warmer weather to get back into this but I had a few questions. 1.) What do you recommend for gear oil as I'm not sure what the dealer had put in it since I bought it at a Lexus dealership I'm just going to drain it. 2.) What's the best method to inspect the shift linkage as I couldn't see anything wrong underneath when I inspected for leaks. 3.) What could of caused the loss of transmission fluid if I don't see any leaks? 4.)I'm also at 105,000 miles so what service should be done such as timing belt, tensioners, and the like as this is my first car that isn't from 1990 or earlier? 5.)Lastly I just read Brendan's STI 6MT Swap and feel inspired to try it if it's a transmission failure as the trans has always had a certain noise that bothered me and was making funny noises every so often for a month before this when I would drive it. So the question is what's the better option if I don't have the skills, space, or tools to do most of that swap myself?

It's a 2010 Subaru legacy 2.5 gt limited with the 6mt. I've had it for 3 years with a slight scraping noise that sounded like a loose heat shield. So I asked a tuning shop and they said to try the clutch so I got a stage 2 clutch put in and was told the transmission is naturally noisy because it kept causing my accessport to go out of tune due to noise. I thought it was strange but didn't see anything online and didn't have issues until about six months ago when the noise got worse and I noticed it was only while it was in gear and got louder when I hit the gas. I only drove it when necessary and Subaru said everything was good when I got the air bag recall done. The day this went down I also heard a jet noise that went with how hard I hit the gas pedal. As for what happens is I'm locked out of every gear but 2nd and neutral. The shifter will not go anywhere else but that path and the mysterious missing transmission fluid is also bothering me not that I ever checked it but I did bring it to Subaru twice a year. I am also unsure how the cable shift linkage works but a friend said it might count on the oil for pressure. Anyone have any ideas?

I had a recent issue with gear loss in my 2010 legacy gt 6 mt. I was leaving somewhere and it wouldn't go into reverse so I let it roll back a little and tried again this time it went into reverse with a clunk and what felt like a stuck emergency brake that went away after I reset the button. So I get to the exit of the parking lot only going into second gear and find out I can't go into first gear anymore. Upon further inspection I've lost first, third, and fifth gear but I continued to go home using second and fourth mainly but lost fourth and sixth about a quarter mile from home so I proceeded in second where I realized I also lost reverse. I now currently only have second and neutral and when I checked the dipstick it was bone dry with no signs of leaks and Subaru saying it was fine when they checked it 3 months ago. So questions are should I try adding fluid hoping it's just not enough fluid to pressurize the gear shifting mechanisms or if it's shot how hard is swapping in the spec b transmission for a stronger transmission with better gearing if I had spec b axles, transmission, and rear diff?