Accidentally grinded 1st gear
 

I accidentally grinded 1st gear during a 2nd gear downshift when coming to a stop. Now, I usually never downshift into 1st unless the car is basically crawling, and I'm not sure why I did it this time, but I was going less than 10mph. SRM was on too. It's a new transmission with about 7k on it and this is the first time I ever grinded a gear with it. Should I be concerned about any long term effects that this may have caused on the synchro or gear? Doesn't 1st gear have triple-coned synchros or something like that?

It's been fine ever since. No popping out of gear or grinds. I just can't get the thought out of my head that I grinded 1st by accident. Appreciate any input.

You should be fine. Don't ever downshift into first. Even if you are going 5mph you can still roll out in second without slipping the clutch.

SRM doesn't match for first gear. Blip the throttle as you shift into first.
I'll be alright. Just don't do it often.

Yes it does. Just not well. It wants a little more throttle than SRM gives it, so I always blip the throttle as you noted.

The car will be fine, OP. But if you're grinding while shifting, you're most likely doing something wrong. Either do it right or don't do it at all :twocents:

You are fine if you do it once or twice. More repetitive actions and it can get damage. You should be fine.

Thanks, I appreciate the feedback guys.

For the record I usually never downshift into 1st. Not sure what came over me but I thought I would give it a shot. I figured with SRM on, it wouldn't be too bad. Without SRM I would have definitely rev matched it myself. Oh well...

Just out of curiousity, how would one be able to tell if 1st gear is going bad? Typically with other gears we're able to tell when we upshift or downshift, neither of which can really be done with 1st gear since it's usually engaged at a standstill. If 1st was faulty, I'm guessing it would just not engage (in a standstill) or pop out of gear?

If it's a one time thing I'm positive it'll be fine. I would think that manufacturers make these with enough durability to factor in the occasional grind. I actually thought 1st gear did not have synchros in the first place but I could be wrong. If it doesn't grind when you place it in first gear or if it doesn't pop out of gear, then move on and forget this happened.

As others are saying don't make a habit of it but don't worry about it. Manual trans are pretty tough all you did was grind the synchro teeth together for a moment. Not good to do in a daily basis but it will take way more than one time to ruin the synchro, think about all the miss shifts and hard shifts done at the drag strip and the trans not needing to be rebuilt after one run.

Appreciate the feedback again.

Maybe I'm paranoid now but I'm finding it hard to get into 1st gear at around 8mph "just to see" with SRM on. But putting it in 1st at 5mph is easy. Normal?

I would say yes. Pretty much every MT I have ever driven doesn't like going into 1st when moving above ~5mph.

1) It was probably that way before the "incident."
2) Don't shift into 1st until you stop.

Unless you forced it into gear or continued to grind the gears/synchro, what you did is considered normal wear and tear. Avoid it if you can, but don't freak out when it happens.

No offense but is this your first manual? You never ever want to shift to first while still moving. Never had a manual or driven a manual of any customers car of any brand that will allow you to shift to first while moving. Put it in first after you have stopped.

yep after 5mph there's a good amount of resistance when trying to back into 5th

Shifting into first while moving is not that big of a deal ... if done properly.

I recommended that OP not shift until stopped because he/she doesn't seem to have a lot of experience with a manual. I've downshifted many manuals into first at "high" speed - you just have to time it right (and maybe do a little fancy foot work). With some practice, OP should be able to do so too.

But I haven't driven a manual 370Z and maybe there's something special about the 6MT, so YMMV.

I feel like I incriminated myself making this. To put it out there, I've been driving manual for 12 years. Maybe it was stupidity that came over me but that one time I just thought I would put it in 1st gear since SRM was on and I thought it would do its job. If you'll read the first post I said I normally never engage first when moving anyway. Oh well, what's done is done. I do appreciate everyone's feedback on this though.