My tranny was slightly notchy in all gears until about 2500 miles (I assume because it was new and tight). From 2500-6000 miles it was superb in every gear under all conditions - a truly wonderful gearbox IMO.

Since 6000 miles I sometimes had trouble getting into 6th whilst accelerating quickly (e.g. when I went through 1st-3rd or 4th and then skipped to 6th at 80mph or so). It felt like I was locked out of 6th (like the lockout for reverse), but hitting the clutch a 2nd time always made it work. Dealership could not reproduce problem.

Since 6500 miles to present (7300 miles) I get a grind when moving into 6th gear. It happens every single time under every condition. It is so consistent I can do tests around it: clutch fully down as far as it can go right to the floor (grind), high speed move from 4th to 6th or 5th to 6th (grind), low speed gentle move to 6th at 2500rpm from 5th (grind), count 2 secs before moving stick out of neutral to 6th (grind) etc.

The only way to avoid the grind is to double clutch (clutch in, move to neutral from lower gear, clutch out, clutch in move to 6th, clutch out). Every other gear is fine under all conditions and driving behaviour, so now I am mostly avoiding 6th altogether.


I did a search and it seems some people with grinding in certain gears need a new gearbox. Am I one of those people?




'04 G35 Sedan 6MT in Diamond Graphite/Graphite with Premium, Nav, Aero
'02 Acura MDX Touring in Redrock Pearl/Saddle with wood bits, cargo stuff

 

Yes you are. I had the exact same problem and my stupid dealership said that that was normal. B.S. I brought it in again and this time they kept it for 3 days and said that Infiniti wanted the tranny back so that they could investigate. They put a brand new tranny in it. You need to go to the dealership and get it replaced ASAP!

 

That's what I feared. I've booked it in for Tuesday. Let's see what happens.

'04 G35 Sedan 6MT in Diamond Graphite/Graphite with Premium, Nav, Aero
'02 Acura MDX Touring in Redrock Pearl/Saddle with wood bits, cargo stuff

 

Don't jump to conclusions. Many people have resolved this issue by realigning their shifter guide plate including myself. There are some legitamate tranny issues, and you may get a free tranny out of it, but usually that's with tranny's having issues in 2nd or 3rd gear. The 5th or 6th gear grind most likely is an issue with the guide plate. If you want directions on how to do that, please let me know. It worked for me. Especially, because I don't feel like removing my nitrous kit to go to the dealer.

’03 G35S 6MT, black/black:
-Zex n20 Kit 150-shot & Bottle Opener
-Amsoil Air/Oil Filters & Oil
-Digital Nitrous Pressure Gauge & A/F Switch/Gauge
-Pressure-based Bottle Warmer
-MSD Window Switch

 

Berlin,

What's happening on the 2nd and 3rd gears of those replaced trannies? I just want to make sure that I don't have another messed up tranny.

Thanks.

 

Tell me more about the guide plate and how to adjust it.

'04 G35 Sedan 6MT in Diamond Graphite/Graphite with Premium, Nav, Aero
'02 Acura MDX Touring in Redrock Pearl/Saddle with wood bits, cargo stuff

 

Just got home. I;ll post in the morning.

’03 G35S 6MT, black/black:
-Zex n20 Kit 150-shot & Bottle Opener
-Amsoil Air/Oil Filters & Oil
-Digital Nitrous Pressure Gauge & A/F Switch/Gauge
-Pressure-based Bottle Warmer
-MSD Window Switch

 

150 shot ? jesus h christ, do you have brand new internals or something ? can it take that much ?

 

To find the steps to align your guide plate you can use the document at the following link:

http://www.rogueengineering.com/pdf/...er_install.pdf

It will talks about how to install a short shifter, but you can use a majority of the information to tell you how to take apart the top of the shifter and align the guide plate. It's really easy. Specifically, you should follow steps 1-7 and then skip 8-12, and continue with steps 13 (which is the guide plate alignment) - 14 to finish. I had to try to align it several times and and go for test drives to make it work. I still get a little grind every once in a blue moon, but it is 95% better. If you can't seem to get it to work, then a trip to your dealer would be advised. Unless you don't want to even mess with it in the first place and have the dealer do it, but like I was saying, I can't take it to the dealer because of my mods. Good luck. PM me if you have any questions.

’03 G35S 6MT, black/black:
-Zex n20 Kit 150-shot & Bottle Opener
-Amsoil Air/Oil Filters & Oil
-Digital Nitrous Pressure Gauge & A/F Switch/Gauge
-Pressure-based Bottle Warmer
-MSD Window Switch

 

That's funny preacher, that u say 'jesus h christ', kind of contradictory to your username. To answer your question about the nitrous,

1. There are many people running n20 on their Gs and Zs all the way up to 350 shot (which blew the engine). Most people run between 75 - 125 with a few others running 150 - 175. Not too many running above that.
2. So far the N20 has been safe on my car as well as on the others who are running the big shots (125 - 175). As long as you tune properly and keep proper air-fuel ratios, it is just as safe, maybe even more then running a turbo or supercharger.
3. Nitrous is a lot more inexpensive than turbo's or superchargers, especially, since I am getting sometimes more power than those using those other mods. The only thing is that I can only have the power for about 15 seconds or so, where those other mods give it to you all the time. (Andy you have to always refill the bottle).
4. When running anything over 125-shot, the clutch and traction become the weak points. If you spray in 1st or low 2nd gear, it is difficult to keep the tires from spinning (without drag radials) and you may run into clutch slip (almost definitely if your running 150 or 175 shot). I have some goodyear GS-D3 wide tires and I still spin the crap out of them if I am not careful.
5. I have heard that the G's engine is pretty solid up until about 450 horses or so on stock internals. I am running stock internals. They do have pretty skinny/weak rods and that is where the problems are mostly. But then again, I am pushing over 400 (crank hp) with the nitrous and had no issues. The others running 175-shot as well as some of the trubo people that are getting up to mid 400's at the wheels are not having any issue yet only a few bad reports of people blowing their motors due to improper tuning.

Do some searches out on this site as well as my350z.com and you'll see all the info on how to run nitrous on our cars. my350z has a post called "the big bad nitrous post" as well as a specific section just for nitrous.

’03 G35S 6MT, black/black:
-Zex n20 Kit 150-shot & Bottle Opener
-Amsoil Air/Oil Filters & Oil
-Digital Nitrous Pressure Gauge & A/F Switch/Gauge
-Pressure-based Bottle Warmer
-MSD Window Switch

 

UPDATE

Took my car in to SouthWest Infiniti to see Tanya this morning. She was smart enough to ask a service guy to drive the car with me in it to see if he could reproduce the problem. He takes off and runs through the gears stopping at 5th and says he doesn't see the problem with 6th gear. I say "Dude - you're only in 5th!". He puts it into 6th and there is the usual crunching sound. Lucky I was with him.

I tell him the various things I've heard on the forums about what might be the problem:
1. might need adjustment of gate
2. might need new synchro for 6th
3. might need complete new transmission

He tells me that Infiniti won't let the dealerships take apart the gearbox to try to fix it - they can only replace the whole thing (and apparently Infiniti have released a new transmission since the early 2004 6MTs came out to fix issues so I would be getting that one). Infiniti also wants the transmission sent back to them for analysis to figure out why the problems are occurring (possible future recall?).

So I kept my car until the parts come in. Just heard from Tanya that I need to bring the car in on Monday morning for a new transmission and clutch, and I can have the car back on Tuesday (will get a loaner of course).

Aside from the annoyance of my tranny going bad (and I never did any high rpm clutch dumps, or racing/auto-crossing etc), I have been very impressed with the Infiniti service and immediate response. I suppose the transmission issue could befall any car (except Lexus of course) - which reminds me my '02 Acura MDX has just been recalled today for transmission issues...:

'04 G35 Sedan 6MT in Diamond Graphite/Graphite with Premium, Nav, Aero
'02 Acura MDX Touring in Redrock Pearl/Saddle with wood bits, cargo stuff