Hi all,

I replaced my transmission with a used unit last week after losing 1st and 2nd gear (would go into gear, but nothing would happen - wouldn't even stall out when applying clutch in gear). I used a generic brand of gear oil for the transmission, 80w-90 GL5 for the swap. I am able to upshift just fine, but down shifting is impossible, basically I'm not able to go from 4th to 3rd at all when in motion, but am able to get from 3rd to 2nd if rev up the engine super high, it will downshift when I'm at a stop.

I bought 2 quarts of Red Line MT90 (75w-90, GL4). Would there be a possibility that this can cure my issue, or would I just be wasting fluid?

Thanks,

-glenn

It sounds like your synchros for down shifting are jacked up. Saying how you have to rev match to downshift. Don't waste your fluid. You might need to find another transmission.

Clutch dragging? How's reverse, Grind or feel the teeth bump a bit before it goes in or slick as snot?
Nope, there's no magic gear oil despite all anecdotal evidence, though there are changes.

Double clutch!

When I rebuilt my engine, I replaced the oil in my trans. Best I could tell, the old transmission oil was the stuff that shipped with the car. I run MT90 in all of my cars, so I poured in 2 quarts in the T50 and figured I was good to go. The result was a really tough time shifting. None of the synchros worked very well, but 2nd and 3rd were particularly bad. I dumped the MT90 and put in 2 quarts of Smitty's 85w90 GL5 and haven't looked back. It shifts like butta as it used to. It took a few miles of driving and shifting (maybe 30-40 miles) for the synchros to get back to working like they were, so you might need to give it a little time to work the old oil out of everywhere.

Thanks, everyone.

allencr, clutch isn't dragging. If I recall, there are no problems in reverse, it goes in smoothly. I have tried double clutching it while downshifting and it still won't let me shift.

Also, when the last transmission went out, 1st and 2nd gear wouldn't work at all, when in gear, and the clutch was engaged, there would be no stalling, bucking, sound, nothing - it was as if it was in neutral. I'd expect if the transmission failed, I would get grinding, and/or it wouldn't let me into the failed gears. Could it be possible that maybe the shifter fork could have became misaligned some how, either at the shifter, or internally?

As a side note: I did not cause this, I sold the car for a DAY and it came back to me like this. I have no idea what happened or how.

Thanks,

-glenn

1st & 2nd could have lost all their teeth, the gears teeth or the syncro's teeth/dogs but unlikely, a broken fork is more likely.

You'll want to avoid using a GL5 oil in the transmission and stick with a GL4. The reason is due to higher concentration of extreme pressure (EP) additives in GL5. These additives eat brass, which your synchros are made of. I've had relative success with MT90 in my Corolla, though the oil can only do so much for a very worn transmission.

I use amsoil MTG. GL-4. Smooth T50, no problems here.

J.A