Wow.. this is finally getting to my coupe.
2 days ago my 6spd was grinding at 3rd gear. Make no mistake, I fully depressed the clutch. It was all the way in and then I put it in 3rd and terrible grinding noise. So I figure hmm well 2nd time is acceptable.

Today I put it 5th gear with clutch all the way in another grinding. My friend was next to me and he heard it too.

If this keeps on happening and happening I will just have to take it to the dealer. This is my 3rd time grinding. But I guess it will happen more frequently. Then I am ready to take my car to get a new transmission..

2003 G35 Coupe 6spd

 

Time for warrenty power! Get that new tranny plus install a lighten flywheel during the operation.

- Don't argue with idiots. They will bring you down to their level and beat you with experience.=P-

 

3 weeks ago I was having a hard time getting from 3rd gear to 6th gear and from 4th gear to 6th gear as well. This was after hard acceleration. I called infinity and they said bring it down. After having it for a day they call me back to pick it up and they said that they test drove another 6mt sedan and they said that it was normal. They also said that under hard acceleration that the syncro's had to catch up. I said ok. Well, two weeks later I am shifting normal and I go to shift into 6th gear and I get a grinding. I said WTF, maybe I didn't push the clutch all the way in. I tried it again from fifth gear to sixth and I made sure that the clutch was pushed all the way in and it still grinded. I called infinity back and they at first said that they already looked at this with my car. I said no you looked at something similiar, but not the same. I brought it back in and by the end of the day they called me and said that Infinity headquarters said to pull the tranny and for them to put a new one in. I said "WHAT?". Well, they had it for 3 days total (because the clutch pedal design was different or something related to the clutch pedal was different) and now my car is perfect. The ORIGINAL problem that I was having is no more, neither is the grinding in 6th gear. Definitely take your car in, you got nothing to lose.

Jon
Pearl White 6mt Sedan
Clear corners
Injen intake
XM radio
Skyline badging

 

I have had similiar problems, except i have only had 3rd gear grinding.It seems to always happen when i switch from 2nd to 3rd under 2000 rpm, quick shifts in that range have led to grinding, it feels terrible. What could be the cause of this, do i need a new tranny as well?
Weird thing is i only get 3rd gear grinding, it might be because i'm shifting to 3rd to early but i dont think this is normal.

 

nope it's not normal at all. You see people have been changing their tranny for awhile now. This was probably pretty common problems with 350Z. Since you can make your car grind show that to your Infiniti service. The only solution is to change the whole transmission.

2003 G35 Coupe 6spd

 

I'm curious, when was your coupe built?
Also, if its cold where you live, how does the new one shift when it is really cold outside?


Laser Red 6MT Coupe / Delivered by Grubbs Infiniti

 

Mine was built pretty early. It is Jan 2003 Model and yes it happened when it was below 30. But the 5th gear grinding was around when it was 40 degrees. Fortunately it didn't happen today. I don't really care about transmission replacing. I actually want a new transmission because I have been abusing my clutch a little. hehehe

2003 G35 Coupe 6spd

 

That's normal, well it kind of is. Here what is happening. The griding noise will happen in any gear if you do it. You're actually causing the noise by the way you are shifting. Here is how it works. It really causes no damage to the tranny if it only happens a few times. The clutch has blockers on it that when depressed and the shifter is in the neutral position (in between the gears going into your next gear) the blockers match up to speed so when you shift into your next gear your clutch can grab the gears without grinding them. The blockers need a split second between shifts to work. If you shift gears too fast, i.e. from second to third, too fast (not leaving that split second in the middle between gears), the blockers wont work properly and they will omit a short gridinging sound / feel as your stick shifts into third. It should only do it for a second. Basically, STOP DOING IT IMMEDIATLY! It's probably your shifting, don't be ashamed, we all mess up our tranny's. This car does have a tough tranny [img]/w3timages/icons/frown.gif[/img]. Concentrate on quick shifting but leaving your stick in a neutral position between the gears for a split second for the blockers to work. I guarentee you will never ever hear this sound again. Go easy (it's not a Porsche tranny), or get a new tranny.

Thanks - Joey Avino

 

malx,

No offense, but you sound like someone who got a 2 minute explanation from a mechanic and is now trying to explain it to everyone else.

Grinding is caused by weak or worn synchros (not in all cases, but definitely in the majority of cases here). Blocker is a good term, but it's totally unrelated to the clutch. Go to howitworks.com and look up the operation of a manual transmission. They can explain it much easier than I can do here.

Bottom line is that even fast shifting should cause absolutely no grinding. You should not have to delay your shift to avoid grinding.

I remember reading a few months ago that your tranny had started to grind. Did you ever get it repaired or replaced? I hope you didn't let the dealer blow you off and tell you to shift easier...... I realize that this is the first manual trans car you have owned (if I remember correctly), but take it from me-- a properly functioning manual tranny should be able to take abusively fast shifts and not grind. Don't let anyone fool you into thinking that it is acceptable.

 

LOL nah I didn't get a 2 min explanation from the service guy. That's always a good trip though. Maybe I'm wrong which is a possiblity, that's why no one should ever kill themselves over my word. However everyone can probably agree that our tranny is pretty tough on shifting. Since it's so mechanical, couldn't shifting faster make it more likely to do more harm than good then in turn causing the grinding noise? I do suggest taking it to Infiniti and making them fix it, and you're right fast shifting shouldn't cause grinding, but it does. Why kick it when it's down you know?

Thanks - Joey Avino