Nismo 6mt owners: Excessive transmission chatter?

Rahul718

2nd gear at 1200 rpm is definitely not lugging, at least I wouldn't think so. It's the equivalent of coming to a rolling stop and accelerating out in 2nd gear. 3rd gear at 20 mph also results in this chatter, which I also don't consider lugging esp. since it's higher than the manufacturer's recommended shift point. If someone could try to replicate this under those situations and report back, that would really help me troubleshoot.

Also, the dealer had their master tech ride with me, the same guy who performed the transmission replacement. He saw exactly when I shifted and didn't say it was too low or an rpm but seemed puzzled why the chattering was happening.

Again, it's a heat issue and only happens after the car has been driven a bit. The noises I'm hearing usually only happen with an aftermarket flywheel setup, it shouldn't happen with oem stuff.

Whtciv2k

Hrm isn't 3rd gear at 20mph too low of a gear?

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370z 6MT

NismoNY

I wouldn't say so. When I drive locally, I turn onto streets in 3rd gear at ~15mph or so and the car feels fine. I never listened for the noise though

JARblue

My stock clutch ONLY chatters at low RPMs (or idle). The more throttle applied at low RPMs, the more chatter. If you're getting on the throttle at all while at 1200 RPMs (in any gear), that is lugging and definitely causing the chatter. The Z likes high revs. I make casual shifts around 3-4K RPMs, meaning my next gear engages near 2500 RPMs or so. Shifting in this manner virtually eliminates all chatter on the stock clutch in every gear except 1st.

You're just fine at 20 mph in 3rd gear. The owner's manual says you can be in 6th gear at 35 mph. I definitely don't make it a habit, but I have done a 1st to 6th shift before

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Rahul718

Thanks Jar. Do you happen to notice if this is a temperature-related issue with your tranny, meaning, it won't happen the first few minutes of a cold start but will start chattering when it gets driven more? That's exactly the case with mine... first few minutes it's quite and no chatter even if I lug the engine. But if I lug the engine with low rpm once the car gets hot, it will chatter like I have an aftermarket clutch/flywheel

Davey

The sound I have heard from a hot Z trans like this is under very little load at low RPM in a low gear, i.e. maintaining 10 mph in 2nd gear, barely on the gas, etc. If you actually step on the gas, you don't hear it. I think the best guess I've heard is that it's the input shaft bearings, which is why it does it more when hot vs. cold, and I think a small amount of it is normal (I've heard multiple Z's do it.)

If you're really hearing it chug away like a Model T when you step on the gas and you're not lugging the engine hard, you might have a trans that's on the worse end of tolerances, I suppose. It could also be knock. Or, it could be clutch/flywheel chatter. It's really tough to say.

You never noticed this with your previous trans, I take it? If that's the case, I would take a wild-*** guess and say your new trans input shaft is way on the loose end. Sounds like the tech didn't like the sound of it, so hopefully you get a better replacement trans?

Rahul718

I hope I get a replacement for the replacement but I don't know how inclined Nissan will be to approve 2 replacement in 1 month. My fear is they will tell me it's normal after their evaluation and I'm stuck with a flawed tranny.

Hopefully they will get back to me today with some news. I think they might call the regional service tech if they're stumped

Rahul718

Dealer gave me the car back today. The tech explained to me that because the transmission is loosely meshed at that rpm and that low speed, it'll rattle more. I'm not too pleased but they told me to stop by tomorrow and test drive a brand new 0 mile 2016 Z to see if it makes the same noise.

Can any of you try to see if your car will make this noise? 3rd gear at 1100 rpm with very light acceleration. I'm going insane right now. All I want to know is it other cars do this with the oem setup or not

jaytirbhaw

Can you get this on video ? I'm pretty sure you're hearing normal transmission noise, these cars are really clunky and noisy

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Rahul718

Tried man...video isn't picking it up properly