2014 Nismo with possible Synchro Ref issues in 5th gear

Rahul718

In hindsight, it's funny how I made a thread on this exact same concern before I bought the car

Synchrorev match transmission reliability?

JARblue

Yup... I expect there is something screwy with the 4th or 5th gear sensors. I have no idea whether they are replaceable or not.

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JARblue

Did you test drive the car before that thread? If not, that is eerie. You'll note that pretty much everyone said there are very few problems reported with SRM. This is not a common issue.

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Rahul718

Nope, no test drive before I made that thread...

Rahul718

Went out for my lunch break and was able to hop on the highway for a bit so I figured it was a good time to test it out again. High RPM 4-5th gear changes (4k+ and even 6k a few times) and not a single hiccup and I was being very meticulous with making clean gear shifts with clean footwork. I just don't get what would cause this to happen sometimes and other times, not a thing.

Rahul718

Update #128:

Went for a nice morning drive on the highway testing this out. Making sure I shifted properly and cleanly, getting out of 4th and moving it up just enough to not disturb 3rd, and all the way to the right and up into 5th. Didn't happen once and I did a lot of them between 4-6k RPM. So now I'm more inclined to believe it's driver error but I'd still love for someone who knows this car inside to drive the car and confirm.

JARblue: regarding your post about that blip not really being enough... I can replicate that situation all day everyday to that exact blip. Seems if the shifter merely kisses 3rd on its way to 5th it'll give a half blip but if I purposely full on touch the gate of 3rd it'll give a more rowdy rev that you were talking about.

Can someone just confirm if the 4-5 Upshift is really THAT sensitive in regards to not mistakenly touching 3rd at all?

JARblue

Hrm... I don't think I've ever noticed a minimal rev like that. I'm going to try to replicate it this weekend. It does seem like maybe your 3rd gate is too sensitive, but I don't know enough about how it works to know if that's even feasible.

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Rahul718

If you could replicate that in 4th gear at 4k that would be awesome. But just barely minimally touch the gate for 3rd while then going into 5th. Full on touching 3rd will give a rowdy blip, as is the case with mine too

JDubya

This has happened to me before, only the first few minutes after a cold start in the winter when temperatures are really cold. When I say really cold, I mean to the point where the LEDs inside the car (gear indicator, stereo, etc) look like they're struggling to change because of how cold it is. It's not consistent though, other than the fact that I've never had this issue beyond the first few minutes on some isolated days.

I don't know enough to understand any logic as to why the above happens, but I thought I'd share that you aren't the only person this has happened to.

Zoren 370

Never had this issue with my Z. With the video you showed it does look like something is wrong with the sensor being to sensitive.
Tried to replicate this morning even if I shift slowly towards fifth with a pause at neutral did not get any blip on the throttle.
Plus the sound of your rev upshift doesn't sound right. Or It could be just the audio of the video.

Rahul718

What rpm were you doing this at? The issue with me isn't with taking too long during the shift with extended time in neutral. The issue is accidentally very slightly touching 3rd on the way to 5th.

JARblue

Just saw this thread today. Seems very similar.

Question about synchro rev match sensitivity

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NismoNY

Same thing happens to me and only on the 4-5 up shift!

But from some of the replies here, it seems it the 4-5 shift isn't supposed to be that sensitive in regards to 3rd gear.

I've honestly just turned the SRM off and I enjoy it more but I know that's not a good enough reason to not use SRM if it isn't working the right way.

Did you ever end up going to the dealer?

Rahul718

Well, it's been a few days of careful upshifting from 4th - 5th and it's been ok. Maybe it was driver error after all? I do strongly believe that the 3rd gear gate is more sensitive in my car than other Zs. It is what it is.

I figure if something was truly wrong that the SRM light would pop up.

JARblue

I didn't have my Z all last weekend, but I did have several chances to try and recreate your experience over the past several days. I think one time out of probably 50-60 shifts it did something very similar to your video. I don't know that your experience is normal, but it seems that it's not completely out of the ordinary.

I tried all sorts of speeds in shifting, pauses, and even some double clutching in my testing. The SRM response varied slightly depending on my input. Earlier I said that SRM should be extremely consistent. This is true, but only when all the variables are the same. Since the input is changing constantly, it's difficult to recreate the exact circumstances every time. It seemed that minor variances in speed at the time of or acceleration/deceleration prior to shifting would alter the SRM response slightly. Also, the speed of the shift and any pauses in the motion can affect what SRM thinks you are trying to do. I did find it very difficult to set off the 3rd gear gate sensor without a full 1K jump in revs, and it did not seem like 'brushing' against it on the 4-5 shift should ever trigger SRM to think you were going to 3rd gear.

The only suggestion I have is to check the alignment of the shifter assembly. Although, if you are completely stock, I don't see why that would be an issue. Plus it's not uncommon for Nissan to use so much locktite that you have to tear up the stock shift knob to get it off. Not good if you don't have a replacement ready and waiting.

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