6th Gear Syncros going after 5K.
 

Just thought I'd share that I have experienced an issue with the transmission of my 370Z. I think the syncros for 6th are going. I first noticed it when I drove to San Antonio for work and suddenly was scratching going into 6th. Then I noticed that the higher the revs I'm pulling when I go into 6th, the worse it is. That means that a 4-6 upshift will scratch more than a 5-6, and a 3-6 is even worse. I've scheduled a dropoff at a dealership back in Houston tomorrow. I will update you guys, but hopefully it's just an issue with mine since these transmissions have pretty much been in production for years.

A buddy of mine suggested the SyncroRevMatch (SRM) feature, but SRM is really like a overhyped cruise control feature that actuates the throttle and doesn't really do anything to the transmission.

Yeah, the SRM doesn't have anything to do with it, it's controlling the engine which is on the other side of the clutch.

I have a hard time getting mine into 6th sometimes. It doesn't grind but it hangs up on something.

Note that there are less syncro's on the higher gears than there are on the lower ones. 1st and 2nd have 3 syncros, 3rd and 4th have 2. Can't remember off the top of my head but 6th may only have 1.

One possibility is that your clutch isn't fully disengaging. If you are getting grinding of any sort when the clutch pedal is on the floor this could be the case. Does your clutch take up seem like it's right on the floor?

The clutch disengages fine for all of the gears but sixth. The action is high, not low as if the clutch isn't lifting, but I'm sure they'll check the tolerances when they have it apart. Doing a slow, kind of double-clutching, shift-pause-shift will allow you to put it into sixth with no scratching. It's at the dealership right now. I have to wait until Monday to hear back from them. I'll keep you guys updated.

Update
 

I told you guys I'd keep you posted. Nissan is replacing the transmission and I should have my car by Wednesday evening at the latest. I think this is a fluke and I was unfortunate to have had this happen, but am fairly sure it is an isolated incident.

One a related note, the base Sentra SUCKS (would buy a Mazda3i over it every time), but the CVT on the small displacement engines makes them really peppy.

Okay, great. Let us know how it feels after you get it back.

Did they give you the reason why the transmission needed replacement?

Yes, more information is needed about their reasoning for the replacement.

Oh good god.. I hope this isn't a trend.

I have a '04 G35 Coupe.. and have been through 3 replacement transmissions (4 total), and am waiting for this one to do the same thing, as it's always under 20k miles.. the quickest happening in less than 10k. (I was not alone with similar issues according to the popular boards.)

It starts by 5th or 6th grinding on quicker shifts, regardless of the clutch being fully depressed, and consistently got worse after time.

I will say I haven't had any issues getting things taken care of by Infiniti.. they happily replaced the transmission over and over again, with loaner cars and no tremendous hassle on my part, but I would hope that this synchro issue would have been resolved.

I was unable to get firm information on what the problem was, as the dealer would recognize the problem, and initiate the 'fix'.. aka a new transmission.

But this could absolutely be completely irrelevant, and unrelated.. I do not have detailed info on the differences in the two transmissions.

Sentra? Is that the loaner? I was always given a G35 Sedan.. I get that it's Infiniti vs. Nissan.. but a 35k car is the same.. a Maxima maybe?

Although.. we have a 6MT Sentra here at STILLEN.. with some goodies on it, including the loudest f'ing exhaust evar.. and it's yellow and black.. which makes it kind of fun to drive.. the BUMBLEBEE! ;)

STILLEN : Project Vehicles - STILLEN Nissan Sentra SE-R Spec V

Thanks for the replies.

The guy I'm dealt with wouldn't know a syncro from a loaf pan, so I didn't bother. I'll ask the tech when I get it back.

As for the Sentra, it's not a loaner, it's a rental and I had to pay for it up front because the dealership couldn't confirm that Nissan would pay for the repair. Next time (which I'm hoping there won't be) I will demand they pay for it from the start and that they provide an 'equivalent or better' car in the meantime. I nearly called NNA when they said they wouldn't provide the rental up front, but I had to get back to San Antonio by Monday and it wasn't worth the hassle this time. They've already agreed to pick up the bill on the Sentra.

by any chance when you were in 6th gear did it make like a whining noise as you increased your RPMs..? as mine does and im not sure if this is normal

im sorry to have to inform you, but this is not an isolated incident. unfortunatley, the same thing is happening to my car right now. they keep telling me that theres nothing wrong with the car. its doing it from 4-6 and 5-6. they say "im shifting too fast". i think im just gonna have to wait till it gets worse

It was definitely amplified when going two gears in all of my experiences with it. It will continue to get louder and happen more frequently.. eventually getting to the point where no matter how slow you attempt to engage the gear it will grind..

That's disheartening..

I wonder if the new location of the transmission is causing a heat problem?

On a side note Honda replaced a lot of transmissions in the early NSX due to a snap ring issue.

Oh joy,

I drove my 370 from Houston - Austin to drop it off at UpRev today and I noticed second gear increasingly difficult to get into. I felt like I was raping it every time. Kinda made me sick to hear that but I thought maybe I was doing something wrong. I also did notice 6th to be a bit of a biotch to get into sometimes but 2nd just seems way off.:ugh2: