Greetings.
The t5 in my firebird grinds in the 1-2 shift if I shift too quickly. No other gears have any problem and aside from the grinding when shifting too fast, there are no other issues with the transmission. (Just to throw this out there, no, I'm not swapping to a T56)

I've got it out and I am starting to tear it down, but the 1st gear synchro does not appear totally wasted as I expected. I thought the friction material would be worn away. Everything else in the transmission down to the fluid is top notch, looks great, no signs of wear. I took some pictures of the offending gear:

The mating surface for the friction material on the synchro is smooth to the touch, but there is very fine hatching

The tips of the teeth are not pointed, but slightly ground down.

Another picture of the synchro surface and teeth.

This is the synchro ring, the friction material feels like a 300 or 400 grit sandpaper. The teeth on it are not worn.

The wear on the synchronizer teeth of first gear leads me to think that the friction material isn't biting very well, thus, shift too fast and it grinds. I'm not entirely sure what the friction material on the synchro or it's mating surface should look like. I saw in a few other threads that that mating surface should be rough, as if dressed by 400 grit sandpaper, is this correct?

And another stupid question; is the wear evident on the teeth on first gear an issue, is first gear an item that should be replaced?

I know, a lot of dumb questions, I'm on a limited budget and I can't afford to throw money at this car if not absolutely necessary. Your help is appreciated!

 

For some reason the picture of the friction surface didn't appear, here it is:

 

I don't see anything wrong with any of that.

Grinding during shifts, except for the 3-4 shift, is a clutch problem about 99.99% of the time. The other .01% of the time, it's something wrong with the clutch. Do the math.

Specifically, it's not disengaging completely. Might not be "the clutch" itself; might be the pilot bushing/bearing, which also must allow everything to rotate freely; might be the throwout bearing or the fork; but one way or another, it's a problem between the flywheel and the front of the transmission.

Look over the entire clutch system VERY CAREFULLY. I don't think there's anything wrong with your transmission.

 

Clutch, never even thought to look that over. Thanks!

 

Hi.The exact same thing happens with my T5 WC, were you able to fix it?Thanks

 

Yes.

The cutch was not fully disengaging.

It was a combination of wear in the clutch pivot ball, clutch fork, throw-out bearing, and air in the clutch line.

 

I appreciate your response.