Joker1337

So I've put a bit more mileage on my 7 since the weather's gotten better and I don't worry about someone skidding on an icy patch into it.

I've been noticing a really not-fun-issue with the 3rd gear down shift from 4th, it started grinding at times (~50% of the time). I thought it was a synchro ring gone, so to test the theory I tried what I think is double clutching (i.e. depressing the clutch, 4-N, releasing clutch, depressing clutch again, N-3, releasing clutch while rev-matching as best I can) but the results were varied (I tried four times and was successful on tries 2 and 3.) I decided that since I don't like metal-on-metal wear, I would stop down shifting 4-3 until I came up with a solution. Since then I've been running in low RPM 4, downing to mid-high 2, then uping to 3 a few seconds later, which isn't ideal.

If it is the synchro, will "double clutching" (the way I just laid out) work, or am I doing it wrong? Is there anything I can do before I have to pull the tranny (I'd like to postpone that till winter if I have to do it) to delay the issue or stop it altogether? Kentestu suggested in another thread a 50/50 mix of ATF and gear oil (with the idea being that the ATF might clean dog teeth), any experience with that?

Joker1337

Bumpity...

22 views and not so much as a: "Ur doing it wrong"?

gsl-se addict

iTrader: (3)

sounds like a bad synchro to me. Good tranny info from Mazdatrix here:

http://www.mazdatrix.com/g2.htm

john smack

iTrader: (12)

Mine does the same damn thing and it is only in third gear..
I was told that my tranny is screwed so I was just going to use it until it is broke.

bliffle

What kind of transmission fluid (lube) do you use?

Do you customarily snap shift into third?

john smack

iTrader: (12)

I havent changed the tranny fluid since I bought the car
I bought it in October
I will change it this weekend what should I use?
I have a 86 or 87 N/A transmission

j_tso

iTrader: (2)

It does sound like a bad synchro. Also, when double-clutching, when you shift into neutral and release the clutch pedal, rev it while it's in neutral. This spins the input shaft up to match the output shaft, or something like that. Since you said you rev match while going into 3rd, that could be why it's not working all the time.

switching to a better lube could help a little. Royal Purple, RedLine or GM Synchromesh(?) are popular choices.

Joker1337

Thanks for replies!

Will try the rev-match in neutral and see what happens.

bliffle:
I don't know what brand oil's in there, I'm planning on getting it in the air and changing it tomorrow though.
Can you define a snap-shift (dropping from 4 to 3 via rev-match w/o clutch)? I generally just clutch-in, 4-N-3, clutch-out + gas.

Kentetsu

It could be due to weak hydraulics. Maybe try bleeding the clutch system and see if that helps. Otherwise, try the 50/50 mix and that should help a bit...