Status report: On my third transmission. Last one was put it somewhere around 20,000 miles. My first tranny started grinding from 5th to 6th and the second from 4th to 5th.

I just hit 50,000 miles. This transmission has been grinding from 4th to 5th now too for about 10-15,000 miles now...not getting it fixed because the warranty is up. No real problems though if I shift slowly from 4th to 5th...sometimes I just skip 5th altogether. It's become almost second nature to me now and the only time I notice it is on the rare occasion where I'm actually topping out in 4th and need to shift to 5th (somewhere around 120-130mph) At that speed it's impossible to not grind it no matter how long the clutch pedal is down..you just have to slam it in gear..

After 3 trannys, 2 master slave cylinders, 2 steering lock solenoids (that one wasn't under warranty) I think my Z has finally decided to stop breaking...*knock on wood*

BlueZ34, the powertrain warranty is 5yrs/60k. Take it in and get your fourth transmission.

I almost don't even know if it's worth it since the problem isn't getting any worse. And I'm starting to think that the synchros just go bad on every transmission no matter how many you get? But thanks, that is nice to know that at least I have another 10k to go if I still wanted to

2010! 21k miles on the Z. It just started grinding shift in to 5th gear..
Grr. Well . At least I know That it wasn't my fault ..

For those that have to keep replacing transmissions, any chance that maybe it's your driving habit and not the transmission that's at fault? Do you drive hard all the time? Maybe bad habits that you are unaware of? Just things that exacerbates a weak synchro transmission.

No way. Mine ground the very first time I shifted quickly - 99% of the time it's a daily driver - Houston traffic. I can't imaging that's abuse; I could shift my old Toyota Tercel faster than I did this car.

My new transmission has about 10,000 miles on it, and I've never had occasion to shift quickly since replacing - BUT, it's now starting to grind again, but this time ONLY when I downshift from 6 to 5. I depress clutch fully, and shift normally - little grind.

The original problem (upshift from 3 to 5) works fine now. Strange.

--ZOM

If that were the case then your lower synchros would be going bad,
You don't think it's odd that there are so many are 5th gear issues, I have 55,000 on min, a 2010 and am looking at a 2nd replacement and I don't drive it hard. I think we should from a group and get something done with Nissan. this is a build issue not a driver issue. You remember the front end of the 2003 350, Nissan bought you tires and then came up with a fix, $45,000 for mine,,,they need to fix this problem, part of the problem could be that flaky dual mass clutch,,,, :tup:

Do you guys drive with the SynchroRevMatch on or off? Do you shift too slow and let the RPMs drop too much? I don't know. It's just weird that most don't have any issues, but the people that do seem to get it again later. Gears 1-4 have more robust synchros.

I drive my Z hard any time I feel the urge...that's why I bought it. It's a sports car. Not saying I thrash it everyday or anything..I haven't gotten a speeding ticket in over a year :) (knock on wood)

I'd say I drive with synchrorev on about 80-85 percent of the time. The exhaust pops gloriously on the downshifts to stoplights. And seeing as how this thread is eleven pages long it might be a stretch to say "most don't have issues" ..I'd say this is kind of a big deal.

Also interesting to know gears 1-4 have more robust synchros..curious to know how you found this out? Either way..that might help explain why it's been the upper gears with the problems.

My wife made a very good point, THESE ARE $40,000 SPORTS CARS,, meant to be driven. I have heard they use "Paper Synchros" much the same as the clutch material in an automatic, apparently they are not up to the task..
There are tons of complaints on these trannies, I think Nissan need to address this issue. I don't think that we should have to replace the transmission every time we do an oil change, just making a funny here but it's close to that.
They talk about how much HP they can handle, 600hp is what they say, really, how about handling the stock HP...
Maybe what we need to do , and I hate to say this but a class action law suit to get someone at Nissan to do something.
On my old Z cars I got 100,000 plus out of my clutches with no problems and 300,000 on the Tranny,,, maybe it's the noisy *** clutch package that is to blame but it is surely not my or your lack of ability to handle a stick,, I have been driving a stick since the 60"s, lots of old school HP with old school trannys,, never had problems like this,,, Oh God,,, maybe I should have gotten my 370 with the DREADED AUTOMATIC.
NISSAN NEEDS TO FIX THIS CRAP!!! I wonder if they have this problem in JAPAN?

I use synchrorev 90% of the time. It grinded in to 5th gear when S mode was off few times. After transmission gets warmed up, It doesn't grind in to 5th.

I Cold Started my car in the morning, Push the clutch in all the way and started to go through all gears ! It grinds In to 5th gear most of the time. I let go the clutch and push the clutch again, It won't grind.

Grinding and Lollygagging
 

Mine is a base model - no SRM. The grinding is not the same in the new transmission; the first one crunched when upshifting to 5, from a lower gear (3 or 4) - the new gearbox grinds - much less frequently - only when shifting down from 6 to 5. Both issues, however, seem to be related to 5th gear.

The grind happens at about 4,000 RPM I'd guess, less at slow RPMs - goes into gear much easier when "lollygagging."

I have to say honestly that I do know how to shift a manual transmission - been doing that for over 40 years, in a dozen or so cars. This is the first time I've ever noticed behavior like that in a new vehicle.

--ZOM

Sad to say but the 350 and the "G"s have the same issue I think I am gonna Lemon Law my 370 I am not gonna put a new tranny in every 20,000 miles. This will be my 3rd tranny since new 55,000.




Sad to say but seems the 350 and G's

Just saw this post
We lost 5th gear in the race yesterday.
Our transmission had 6 full Continental Sports car race weekends on it as well as about 5 other test days and hours and hours on chassis dyno (5th gear pulls)
For this series....
That is a looooooooot of time on a oem gear box
When I was involved with the 350z program... We got 1 1/2 to 2 races and the synchros were gone.

Dwnshift, do you use the stock OEM gear box as is, unopened. Or do you tear it apart and go through it before the season starts? :tiphat: