2nd gear clunk, rubbing, grind
 

I know there have been a bunch of tranny threads but I can't really find one focused on what I'm experiencing. When shifting to second gear, at least 50% of the time it'll clunk. About 20% it'll clunk and I'll also feel rubbing through the shifter, like metal on metal, not pleasant at all. Sometimes it'll also grind. This is all when shifting first to second. When going third to second it behaves much better. Another thing I've noticed is that the problem is barely noticeable when the car is cold, but when it warms up it gets bad. Whether or not I granny the shift seems to make no difference.

I took it to a dealer, a tech drove it and then gave me the usual about how the tranny is clunky. They let me drive another Z, and while second gear on that one also clunked, I never felt the rubbing or grinding on that one. What can I do about this, it's really starting to piss me off.

I noticed the clunk when shifting from 1st to 2nd a lot. It always happens to me when I'm at low RPMs or holding in the clutch for a while before shifting.

I've also noticed that sometimes when downshifting and the clutch is IN, it grinds so i put it in neutral and try again without releasing the clutch from the first time and it's okay. (this has only happened to me twice so far so I haven't really been worried about it).

i'm also getting the grind/notch going from 1st to 2nd when cold in the morning going to work. it slowly gets better as the powertrain warms up. but this is getting annoying to the point that i'm afraid to shift into 2nd. I wonder how many more grinds can it take before the 2nd gear is gone?

The car only has 600 miles now, would it go away after the break-in? Or is it something that I need to live with? It's as if there is no syncro in the 2nd gear..

What RPM are you shifting into 2nd? It helps to shift at a higher rpm. 4000-4500 rpm shifts are a lot smother the 2500-3000 rpm shifts. If you've researched this topic in other threads, I don't have to tell you how noisy this transmission is. All of the above are unfortunately normal for this car. If you experience any girding in 5th or 6th, have that checked out because it could mean a new transmission is in your future.

in the morning traffic in LA, i usually accelerate very smoothly and shift arouond 2000 rpm.. which is even more puzzling as I would expect grinding would occur in fast/power shifts but not my granny step-by-step shift in heavy traffic...

my 5th and 6th shfits fine. but i'm still in my break-in period so don't know yet how the tranny will behave when I push it hard

the AP1 S2000 I had got a lot of 1st->2nd grind as well when cold. but just not as much and as pronounced as in the Z..

http://www.the370z.com/z1-motorsport...tml#post811416

noticeable difference for me in terms of sound/clunk/smoothness.

I had an 09 base no sport. Clunked all the time like your statement above. Same thing happened to me when I brought to dealer.. All they could say is "that's normal for that tranny". Funny enough.. I traded it for a 40th anniv. and there's absolutely no clunk. I have to try super hard (gunning the clutch at low rpm etc etc) and for the 3 months I've owned it and it has clunked 1 time. The metal to metal feel however is there and there is some grinding from 2-3rd gear.

^ This

The 6MT is very noisy/clunky. Heck, even the Getrag MT82 in my Mustang, which is 100x smoother than the 6MT, still gets that hard/clunky 1-2 shift when the transmission is cold.

:iagree:

When I switched to Redline MT-90 in my Z it was noticeably smoother during cold shifts.

I totally agree. Swap trans fluid man as soon as you can. For one I think Nissan didn't put a whole lot in mine but afte switching to redline MT-85 it is a lot smoother and gave a lot less NOise and vibration clunking etc...

I found out that the grinding only happens if I shift slowly. Ie. gently push the gear lever down, waiting for the rev to drop a bit and let the lever slide into the 2nd gear gate like I usually do.

However, I don't get the grind if I shift faster and push it into 2nd. Would this be bad for the synchro? I learned to shift slowly to avoid grinding on my S2000, but the z seems to like it hard...

Is it better to screw the synchro by shifting fast, or screw the gear by letting it grind?

The grinding goes away once the car warms up though.. it slides into 2nd gear effortlessly when the rev is in the right range..

honestly get the fluid changes.. its easily worth it!

go to another dealer.. Im begining to realize the deeler by me is VERY good with warranty work... the littlest complaints by me have all been answered and taken care of...

If theres clunking and grinding you should be entitled to a new transmission

do you remember how many quartz of MTF does the z need? not sure where I can find MT-85 in LA.. will probably need to order it online

the tranny I believe takes 3.1 quarts. so buy 4, dont just go with 3. you will need a hand pump to get it in there.

also you can order from here
http://www.the370z.com/z1-motorsport...ilable-z1.html

since you have a bit extra with the drain plug open. squirt a lil bit into the tranny and let it flow out. then close the drain plug and pump away.

I guess I'll show it to the guys at Criswell Nissan. Also I plan on changing tranny fluid and differential fluid with the next oil change. Thanks.

I would double check the 3.1 wuarts thing!

im almost 99% positive but dont hurt to ask

Changed tranny fluid this weekend. 2nd gear is still a b!tch, no noticeable improvement. Could it be the 2nd gear synchro? All the other gears are fine.

Overall the transmission does shift more easily now when warm so that's good i guess. I had them use a 50:50 mix of Redline MTL (70w80) and Redline MT-90 (75w90)

mixed the oils?????? is that even safe?

http://www.the370z.com/diy-section-d...il-change.html

7. Place the inlet hose of the siphon pump into your fresh container of oil. Start pumping...you'll notice it takes a bit of work to pump the viscous oil up into the transmission. The capacity is 3 quarts and I used a 50:50 blend of MTL and MT-90 since I live in Chicago and experience the hot and cold extremes. The mix will get you a blended viscosity close to Nissan's recommendation of 75w85 (MTL is 70w80 and MT-90 is 75w90). Pump until oil starts leaking around the pump hose from the filler screw hole.

That's because you're granny shifting and not double clutching like you should.

I understand the mixing but the new mt-85 is actually perfect for the tranny. no longer need to mix.

Same thing with me, when I shift faster it works 100%.

Downshift Grinding
 

Hey Guys....
I read all your posts and I have the noisy, clunky, 6MT on my 2009 370z Base model as well....
But mine also grinds into every gear on downshifts. 6-5 is the worst.
It will do this until the PT is good and warm (In my case, thats usually about the first 15min of driving every day).
I have about 25k miles.
I am going to get a flush as soon as I can get the time. But the Mech I took it to said the fluid was dirty and had particles in it.

Now, being an aviation mechanic, darker oil in a semi-closed system is usually caused by contaminants, either metal flakes (minute or not) wearing off gear teeth or they are caused by improper lubricant used in gearbox.
Now, if I have dirt in my system, it obviously got in to the system before I got the car (which I purchased brand new).
I have not been driving around with a dipstick missing or plugs removed.

How the hell could dirt be in the system unless it was in there from tranny assembly at factory?

Thoughts?!?!

Update LS Differential Clunking- Syncro
 

I've had the '14 Z Touring Sport MT for 1100 miles to date.

Here's what I've found:

Shifting at anything below 3K in 1st, 2nd, or 3rd gear will cause the clunking.

Upshifting in normal traffic at 1, 2, 5 and 6 works best for "normal" in city traffic motoring with minimal clunking.

The clunking noise is the synchro and LSD out of sync due to low revs in the lower gears. I'm not sure what the gear ratios are, but I suspect they're high in 1 2 and 3. Higher revs in the lower gears cures all. It's smooth and quiet around >3500 rpms While it's understandable that the Nissan Z engineers designed it as such - it's annoying in slower traffic.

BTW, I checked the differential oil factory fill level at the dealership this week, and it's clear and full with a consistency similar to thin vaseline.

I also had the service manager check with the Nissan "DTM" as I complained at 150 miles about the clunking and mentioned that this forum has multiple threads on the subject, and using different differential and MT fluids - specifically RED LINE. The service manager informed me that NISSAN DOES NOT approve of using RED LINE oils. Of course you might expect that, but this dealership allows customers using their own oils if approved by NISSAN.

I asked them to check if Mobil 1 synthetic LSD was approved.

I'll update this post when I get more info.

The dealer cannot deny warranty service if you use OEM-equivalent fluids, so whatever the service manager told you about Nissan not approving Redline is irrelevant. Redline 75W90 gear oil is perfectly acceptable (and highly recommended on this forum).

I use Mobil 1 for engine oil because I can get 5qt for $25 at Wal-Mart. MT, differential, and power steering fluids are all Redline. Clutch and brake fluid is Motul. The OEM fluids are fine for your car, but my research indicates that Redline and Motul fluids are much better (especially if you push your car) :twocents:

1. That is definitely not good. I thought the factory fill was supposed to be translucent and brownish red. In either case, I use Motul fluids for Tranny and Diff.

2. That guy is full of crap. I have had Mobile 1 and Royal Purple oil changes at the dealership with no issues or warranty threats. I am currently using Motul to keep everything simple.

Holy necrobump. Vin, as long as the replacement fluid is the correct spec, they cannot give you any issues over using non-Nissan fluid unless they provide it at no charge.

Update: Mileage 2850

Changed out factory fill engine oil (Mobil 1), differential, and gearbox today at the dealership.
I replaced the factory fill gearbox oil (clean and clear) with MOTUL Gear 300 and the Differential (metal filings present) with Gear 300 LS.

Observations and experience: Gearbox is much smoother with MOTUL than OEM factory fluid - especially downshifting into 2nd and 1st. There is a noticeable decrease in previous clunking linkage sounds. Linkage noises are still there (design flaw) but not as loud, and shifting feels more precise.

Noticeable decrease in Limited Slip slapping/clunking noises, especially from 1st to 2nd.

I attribute these improvements directly to the MOTUL fluids.


I have a long trip coming up next week, so I'll get to feel and hear more over an extended time frame and over the interstates.

Update to follow.

RJM Clutch Pedal Assembly = shifting is smooth like butter

It was the BEST and first mod I did since I had same issue just like you.
After installing it, no issues at all. Period.

I've been using Motul 300v motor oil since 5K. I now have 47K, motor doesn't use a drop of oil between changes which I do at 4K. Just changed tranny and dif to motul gear 300 75w90 (ls in the dif). Trans fluid was clear, dif not so much. Thick layer of sludge on the drain plug. Shifting is much smoother and dif isn't as clunky. I wish I had changed out the dif and trans sooner.

Update: Mileage 5850

Just got back and the differential and gearbox actually improved!

As posted to another thread http://www.the370z.com/nissan-370z-g...motor-oil.html

I used 8100 Econergy 5W 30 with a Nismo Veruspeed fliter as supplied by Z1 Motorsports on my recent long distance trip. On the first leg I was using 5W30 Mobil 1 and a Nissan OE filter. On my return trip I changed over to Motul and the Nismo Veruspeed. There was a 15 degree difference in oil temp with the Mobil 1 at 220F (max) and the Motul at 205F (max). Both were the same routes and extended duration high speed interstate travel. Good stuff!

Sign-off
 

Update mileage 32800

Traded in today with sadness. She turned out to be a dependable daily driver with a unique personality. NO major mechanical or systems problems EVER!

I'll miss her.