I'm having the same problem with my '04 with about 54,000 miles. It's been happening occasionally for a while now, usually when shifting from 4th to 6th, but I just tested what happens if I try to shift 5th to 6th quickly rather than a bit more slowly and deliberately. When I try to shift quickly it *does* grind on the way in. I've developed a habit of driving around the problem by shifting slowly enough to give the synchros a bit of time to work.

I'm taking it into Crossroads Infiniti of Raleigh for an early 60k service and to check out this problem. They're going to give me a loaner and said if they can verify what I'm saying they'll replace the transmission under warranty.

 

maybe i should take mine in... mine have done it since i got it a year ago

 

Well... they're not going to do it after warranty, and if the synchros are going they won't get better, over time they will get worse. They obviously cost a lot to fix as it involves opening up the tranny. Under warranty they just swap in a whole new tranny. That can't be a bad thing. You sure don't want to pay for it later and they are warranted drivetrain components.

 

Yep.. it's the synchros, and it's most definitely not going away. I would have hoped they would have fixed this problem by now, but it seems like it continues. I guess throwing new transmissions at it is cheaper in Infiniti's eyes.

I have an '04 with 65k miles.. and it has an appointment tomorrow morning, which I'm 90% positive will result in the THIRD replacement transmission on the car, for the exact reasons you specify.

First one was at 19k.. and that was me babying it for 7-8k miles, until it got to the point where even babying it wouldn't stop the grinding from 4th to 5th, and don't even think about going from 3rd to 5th.

Second replacement was I believe 15k miles later.. and this time it's lasted a bit longer, just over 30k miles.. but all with the same result..

My experience has been 5th gear being the main culprit, but grinding has also happened in 2nd and 6th gear. Spirited shifts from 4th to 5th will cause grinding, and half-spirited shifts from 3rd to 5th will guarantee noise.

 

Please do not skip gears.

This tranny is not made to take that kind of abuse. Skipping gears on a tranny not designed for it will lead to VERY premature wear on the.

The vette is specifically designed to allow this; the G is not.


Fortunately, Infiniti is very generous with their warranty.

This is a known issue with MT Hondas, and Honda will not replace a tranny for pre-mature synchro wear. Honda HAS beefed up the synchros, but that alone is not enough to prevent premature wear from skipping gears.

 

I told the dealer about losing power when cornering on the track (I've been out on one track day with the car and it seems fuel sloshing is a problem with the sedan) As a result, they said I was misusing the vehicle and will not warrantee the transmission as a result.

If you ever do any track or HPDE event DO NOT TELL THE DEALER or they will not honor the warrantee. My car now has a dealer record as having a grinding sixth gear and not being warranted due to misuse. Nice.

Sixth gear doesn't even get used on the track, period, and the problem has been around for the last year and is still quite minor but will eventually get worse. A new tranny is going to be on my coin now because I mentioned I'd been on the track!

So much for being generous with the warrantee.

As for not skipping gears, the owners manual describes use of the manual transmission in section 5, mainly on pages 5.13-5.15. There is nothing mentioned about not skipping gears. I agree its a good idea to avoid doing so as it does seem to require a bit more of the synchros but I can't find anything in the owners manual indicating that the car isn't designed to be able to handle it.

 

Is it the dealer or Infiniti that is denying the claim?

I'd be willing to bet it's the dealer. Try another dealer.

The So-Cal guys can vouch for us; we're more than mod friendly


Also, regarding the manual, it gives shift speeds for each gear. Note that it lists EVERY gear, unlike a certain sports car made by Chevy.

 

(I just realized I was looking at the wrong manual, I downloaded the G20 manual. The G35 does say to run them sequentially...)

The dealer's service manager said that the district manager was at the dealership that day for a meeting and had reviewed the case and that it was not warrantable. I called consumer affairs to discuss what had happened (without giving my name or VIN) They said that if the district manager was there, that meant a factory representative and therefore it was unlikely the decision would change. They said I could go to the Better Business bureau to appeal through a channel they have established.

I was thinking of going to another dealer but the nearest is an hour away. If that might work though it's worth a shot, I'm just worried that it goes straight to the same district guy who shot me down already.

Honestly, knowing that I have the prospect of a three grand bill coming at me down the road and with the dealer denying me because I went on the track I'm just weighing my options, de-mod and sell the car, try to get the work done at a dealer 60 miles away, appeal... I dunno what best to do at this point. I already made a bad mistake and I'm afraid to make another. I really like the way my car is set up and I want to keep driving it.

Maybe I should make a road trip to Riverside!! It's only 3000 miles! It's been too long since I've been on one anyway, and I've been meaning to visit the Grand Canyon... you think you can turn me around in a day or two with advance notice?

 

We'd have to get the car here, diagnose it, order whatever is needed provided we get authorization, wait for the parts to get here, and install.

At the least, you're going to have a loaner for a few days

Vacation time?

 

It sounds like your synchros have gone bad... you should not skip gears because of damage to the synchros

 

The factory district manager and the dealership service manager initially decided that since I had a racing clutch and had been on the track using racing tires; that I had therefore been racing; that was misuse of the vehicle and therefore the transmission repair was unwarrantable. They recorded that on my vehicles record, effectively voiding the most important aspects of my warranty going forward and significantly devaluing my vehicle.

I argued that racing is a competition between more than one car and that I had not been racing. I argued that while racing is specified in the warranty as cause for denial, other track use is not similarly specified. I also argued that the problem was not caused by taking the car on the track and that I hadn't even used 6th gear on the track. I also argued that the clutch was functioning correctly and that unless they could prove that it caused the problem that was not a reason to deny warranty either.

I also let them know that I was going to go to arbitrate through an arrangement that Infiniti have available though their consumer affairs and the Better Business Bureau.

The dealer went back to the factory rep and discussed my point of view on the situation with him.

They changed their position and are going to replace the transmission!

They will make another entry on the vehicle's history basically recanting the previous entry, however they cannot remove what they had entered so the car's history has been permanently marred.

Lesson one: Never tell the dealership if you've tracked your car.

Lesson two: Don't give up.

Lesson Three: Never skip gears, it's bad for the synchros

 

The manual also doesn't tell you to not do burn outs, or drive off cliffs, or run over babies for fun.

 

Yeah, yeah...

I'm in agreement, ok?

I will not skip a gear, I will not skip a gear, I will not skip a gear...

 

I'd imagine gear skipping is ok as long as you're pretty much matching revs with the next gear.

I.E. 1st > redline, 2nd > redline, pause and rpms drop to ~2,400 and you put it in 5th @ ~50mph or so.

You can also put GM Syncromesh in if your syncros are grinding and you can't get things fixed under warranty... it made all the gear grinding in 3rd gear in my old VW go away and is commonly used across various makes and models to solve grinding.

 

Finally someone in the know that works in the industry chimes in I tried to tell you guys that skip shifting is not good on this particular transmission.