Thread: b15 trans grinding 3rd gear

My car grinds 3rd if i shift it quick or if the rps are high. It does not grind when granny shifting. What could cause that and how do i fix it? is it the syncros and where can i find them for the b15 trans? also what other gear stacks fit this trans? the qg18de?

Don't think the QG is the same - what gear oil are you running, and is up to the recommended levels? Low gear oil, or crappy cheap gear oil, when it's -10 degrees or 110 degrees over a long period of time can slowly lead to problems

Oh and to find a B15 manual trans, I'd first go to every pull yard within around 40 miles of your house. There are LOTS of B15 Sentras at the 2-3 pull yards I go to, however 90 percent are automatic 1.8's or GXE's or whatever. I saw one '01 2.0 liter but it was auto. Tough to find but can online but not cheap

What gear l are you running? Spending 50$ on mt-90 shockproof or oil of the same quality is worth every Penney. I killed 3 fwd sr20 trans. on a t25 de-t using junk oil. My 370hp det t3/4 trans. with 150k on it lasted 7yrs running shockproof. I noticed the same issue with my 6spd, grinds a bit on cheap oil but not on good stuff.

Here's what I noticed with the CRAP gear oil - when it's cold, it takes about 20 min for the shifter to feel like it would at 70 degrees. It doesn't want to move the colder it gets; on the other side, when it's really hot outside the shifter feels kind of sloppy. So I went and got this:
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Now that stuff isn't cheap. About $88.00 for 1 gallon of it on Amazon. I'm not sure how much the B15 SR20 gear box takes but the B13/B14 takes 4 quarts (or the whole gallon) - and enormous difference. Shifts feel more precise.

OP, I'd get some good oil like the NEO or what @se200 suggested and see if that helps

Ok i will try the gear oil first. I have no idea what oil is in there or how much. I just get in this car and drive it lol. Its been very good to me for over a year now.

Chances are its prob cheap oil. Did you get the clutch changed at a shop or anything? They will put the cheapest crap they have in there to keep costs down