Sticky: 370Z Transmission Failures (6MT)

DIGItonium · 08-21-2012, 12:20 PM

Let's sticky a thread that lists owners who experience 6MT transmission failures. We'll list part numbers here in case Nissan decides to rev the part number. Hopefully we can gather some failure stats. Nissan pretty much needs to do something about these craptastic synchros.

ID: 320B0-1EA0B
Purchase Date: 04/17/2009
Type: Sport

Replacement #1 (05/18/2012)
I started having 3rd gear grind that progressively got worse. It would be fine early in the morning, and then it would grind above 3k RPM. As it got worse, it grinded all the time. Also, the high RPM 1st to 2nd shift and 2nd to 3rd would grind or lock me out. Gearbox was pretty notchy as well. The transmission was replaced along with a new ceramic clutch disk, master cylinder, and a revised HD CSC.

Replacement #2 (08/30/2012)
A month after the replacement I notice 5th gear was a bit difficult to get into half the time regardless of load or RPM. I thought it was normal notchiness, which is nowhere near as bad as the original transmission (all other gears are smooth). Interesting enough, SynchroRev would rev up twice before I was able to get into the gate. The summer has been pretty hot so I've not driven hard as often, nor have I been out to the strip. There were times it wanted to pop out of gear. Then 2nd started grinding and locking out at high revs. I replaced the fluid with Redline, and it smoothed out the gearbox nicely. However, it didn't help with the occasional 2nd gear grind at high revs or 5th gear lock out. Although it never grinded, the 5th gear lockout was getting worse. My tech took it out last week for a test drive and freaked out when he had trouble down shifting into 5th while exiting the freeway. He couldn't force it in at all as if the synchros weren't there, so a new transmission is on order for this week.

I also went ahead and ordered Motul and Redline fluid for the clutch and gearbox.

[Update] New transmission installed with fluids. This gearbox feels very different. It is not notchy, but there is more resistance and you can feel the gears. There is slight whine in 2nd. Although I am able to shift well now, I miss the buttery ease of the last transmission. I'm going to let it break in and see how it goes from there. part number is the same.

anthonyy · 08-21-2012, 01:48 PM

Quote:

Originally Posted by DIGItonium

Let's sticky a thread that lists owners who experience 6MT transmission failures. We'll list part numbers here in case Nissan decides to rev the part number. Hopefully we can gather some failure stats. Nissan pretty much needs to do something about these craptastic synchros.

ID: 320B0-1EA0B
Purchase Date: 04/17/2009
Type: Sport

Replacement #1 (05/18/2012)
I started having 3rd gear grind that progressively got worse. It would be fine early in the morning, and then it would grind above 3k RPM. As it got worse, it grinded all the time. Also, the high RPM 1st to 2nd shift and 2nd to 3rd would grind or lock me out. Gearbox was pretty notchy as well. The transmission was replaced along with a new ceramic clutch disk, master cylinder, and a revised HD CSC.

Replacement #2 (08/XX/2012)
A month after the replacement I notice 5th gear was a bit difficult to get into half the time regardless of load or RPM. I thought it was normal notchiness, which is nowhere near as bad as the original transmission (all other gears are smooth). Interesting enough, SynchroRev would rev up twice before I was able to get into the gate. The summer has been pretty hot so I've not driven hard as often, nor have I been out to the strip. There were times it wanted to pop out of gear. Then 2nd started grinding and locking out at high revs. I replaced the fluid with Redline, and it smoothed out the gearbox nicely. However, it didn't help with the occasional 2nd gear grind at high revs or 5th gear lock out. Although it never grinded, the 5th gear lockout was getting worse. My tech took it out last week for a test drive and freaked out when he had trouble down shifting into 5th while exiting the freeway. He couldn't force it in at all as if the synchros weren't there, so a new transmission is on order for this week.

I also went ahead and ordered Motul and Redline fluid for the clutch and gearbox.

jeeze... sorry for your troubles. Nice thread... hopefully there won't be too many bumps

BGTV8 · 08-21-2012, 04:51 PM

I now have the crunchies on skip shift from 3rd to 6th at max-revs (like accelerating the car up to speed on the on-ramp to freeway and then slot into 6th at 110kph). Car has 70,000klics on it. So far, only 6th affected.

Have gone to Motul gear oil and is "better" but not perfect. I have an extended drivetrain warranty (up to 150,000 klics) on my car and will be hassling Nissan about it at the next serice, but the car has seen a lot of arduous service (track days and speed events) so I'm optimistic about a Nissan repair .. we'll see.

GaleForce · 08-21-2012, 05:22 PM

I got a bad crunch going 1st to 2nd at high revs. I'd bet I have transmission troubles, I'll have to do more testing first. Is this covered under the extended power train warranty?

DIGItonium · 08-21-2012, 05:42 PM

The 1-2 shift at high RPM is terrible. It is a hit or miss. My tech couldn't nail it either, and it was easy when the transmission was new. It literally locks out and grinds half the time to the point my hand would slip off the shift knob. Before the last transmission was replaced I didn't recall having a successful 1-2 upshift. 3rd would lock out and grind until the revs went down to 2k or so. Even if I did get in 2nd, it would grind going in.

One of the members here had his synchros switched out for ones sourced from Ford Racing, and it shifts like a champ. However, it is currently cost prohibitive which is around $2k. Maybe someday... but not after getting my own pad haha. I don't even have sod and sprinkler in yet.

Rui Z · 08-21-2012, 05:50 PM

Quote:

Originally Posted by BGTV8

I now have the crunchies on skip shift from 3rd to 6th at max-revs (like accelerating the car up to speed on the on-ramp to freeway and then slot into 6th at 110kph). Car has 70,000klics on it. So far, only 6th affected.

Do not skip to 5th or 6th gear on the Z. It is known to have weak 5th and 6th gear synchros. You will wear out the synchros.

Davey · 08-21-2012, 06:02 PM

Quote:

Originally Posted by GaleForce

I got a bad crunch going 1st to 2nd at high revs. I'd bet I have transmission troubles, I'll have to do more testing first. Is this covered under the extended power train warranty?

Yes. It is covered to 60K miles... It's not a wear item, it's part of the powertrain, fully covered!

GaleForce · 08-21-2012, 08:04 PM

Quote:

Originally Posted by Davey

Yes. It is covered to 60K miles... It's not a wear item, it's part of the powertrain, fully covered!

Good to know, thank you sir

IDZRVIT · 08-24-2012, 08:39 AM

If you beat on your tranny, don't know how to shift (yes, there are some in here) or add lots more HP/TQ it will probably have issues because it wasn't designed for that. I don't have any issues except the odd clunk and it shifts as well or better than any manual I've ever owned even at redline. But mine is not FI. By comparison, my 2011 Civic's MT/clutch is a pos compared to my Z. You get what you pay for.

Red__Zed · 08-24-2012, 08:55 AM

Well known that the Z has crappy synchros.

They toughened up the 5th gear synchro in mid10 and again in early 11. By all measures the mid11s seem to have dramatically better 5th gear behavior.

2011 Nismo#91 · 08-24-2012, 10:35 AM

I occasionally grind 1st to 2nd but I attribute that to lack of attention rather then the syncro because its not consistent. Pretty much happens in all my past cars.

I don't see an issue skip shifting if you give the time to match revs.

SPOHN · 08-24-2012, 10:59 AM

I'd like to know with what people have had problems do they have SRS?

IDZRVIT · 08-24-2012, 04:23 PM

I doubt SRS has anything to with it. All its doing is revving the engine to make a smooth downshift which is a benefit if anything by reducing stress. Now if there were some mechanical linkage then there might be a cause for concern but there isn't. It's all electronic. No car is bullet proof. If you beat on it beyond its design parameters its gonna break. Open up your wallet and don't expect the warranty to cover it.

DIGItonium · 08-24-2012, 06:14 PM

Haha I don't beat on my car that much even with FI. I haven't even tried dumping the clutch or drag race. The summer heat has been a record breaker so I don't get to drive as hard. My car has lots of freeway mileage. Plus 5th isn't even a gear I would race in. It's just a daily driver to and from work. My tech knows I baby this car lol.

Telephone · 08-24-2012, 08:30 PM

Downshifting into 5th during normal driving can be a pain. It's hit or miss really. SRS is always OFF.

Is this tranny used in any other Nissan/Infinity model? If so, are there other complaints?

08-21-2012, 12:20 PM	#1 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 42	Sticky: 370Z Transmission Failures (6MT) Let's sticky a thread that lists owners who experience 6MT transmission failures. We'll list part numbers here in case Nissan decides to rev the part number. Hopefully we can gather some failure stats. Nissan pretty much needs to do something about these craptastic synchros. ID: 320B0-1EA0B Purchase Date: 04/17/2009 Type: Sport Replacement #1 (05/18/2012) I started having 3rd gear grind that progressively got worse. It would be fine early in the morning, and then it would grind above 3k RPM. As it got worse, it grinded all the time. Also, the high RPM 1st to 2nd shift and 2nd to 3rd would grind or lock me out. Gearbox was pretty notchy as well. The transmission was replaced along with a new ceramic clutch disk, master cylinder, and a revised HD CSC. Replacement #2 (08/30/2012) A month after the replacement I notice 5th gear was a bit difficult to get into half the time regardless of load or RPM. I thought it was normal notchiness, which is nowhere near as bad as the original transmission (all other gears are smooth). Interesting enough, SynchroRev would rev up twice before I was able to get into the gate. The summer has been pretty hot so I've not driven hard as often, nor have I been out to the strip. There were times it wanted to pop out of gear. Then 2nd started grinding and locking out at high revs. I replaced the fluid with Redline, and it smoothed out the gearbox nicely. However, it didn't help with the occasional 2nd gear grind at high revs or 5th gear lock out. Although it never grinded, the 5th gear lockout was getting worse. My tech took it out last week for a test drive and freaked out when he had trouble down shifting into 5th while exiting the freeway. He couldn't force it in at all as if the synchros weren't there, so a new transmission is on order for this week. I also went ahead and ordered Motul and Redline fluid for the clutch and gearbox. [Update] New transmission installed with fluids. This gearbox feels very different. It is not notchy, but there is more resistance and you can feel the gears. There is slight whine in 2nd. Although I am able to shift well now, I miss the buttery ease of the last transmission. I'm going to let it break in and see how it goes from there. part number is the same. __________________ Last edited by DIGItonium; 08-31-2012 at 11:17 AM.

08-21-2012, 05:22 PM	#4 (permalink)
GaleForce A True Z Fanatic Join Date: Aug 2011 Location: Ontario, Canada Posts: 21,749 Drives: Varis Arising II Rep Power: 51864	I got a bad crunch going 1st to 2nd at high revs. I'd bet I have transmission troubles, I'll have to do more testing first. Is this covered under the extended power train warranty? __________________ >>>GaleForce's Build<<< >>>FaceBook @3GsCustoms<<<>>>Instagram @GaleForce370z<<< Varis Kamikaze-Z

08-21-2012, 05:42 PM	#5 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 42	The 1-2 shift at high RPM is terrible. It is a hit or miss. My tech couldn't nail it either, and it was easy when the transmission was new. It literally locks out and grinds half the time to the point my hand would slip off the shift knob. Before the last transmission was replaced I didn't recall having a successful 1-2 upshift. 3rd would lock out and grind until the revs went down to 2k or so. Even if I did get in 2nd, it would grind going in. One of the members here had his synchros switched out for ones sourced from Ford Racing, and it shifts like a champ. However, it is currently cost prohibitive which is around $2k. Maybe someday... but not after getting my own pad haha. I don't even have sod and sprinkler in yet. __________________

08-24-2012, 08:39 AM	#9 (permalink)
IDZRVIT A True Z Fanatic Join Date: May 2009 Location: Halifax Posts: 1,659 Drives: '13 CTS-V, '76 Vette Rep Power: 26	If you beat on your tranny, don't know how to shift (yes, there are some in here) or add lots more HP/TQ it will probably have issues because it wasn't designed for that. I don't have any issues except the odd clunk and it shifts as well or better than any manual I've ever owned even at redline. But mine is not FI. By comparison, my 2011 Civic's MT/clutch is a pos compared to my Z. You get what you pay for. __________________ "America.... still builds rockets!" Vette: 355 cid, 400 rwhp '13 CTS-V Coupe: 6.2L LSA, 556HP

08-24-2012, 10:35 AM	#11 (permalink)
2011 Nismo#91 A True Z Fanatic Join Date: Mar 2011 Location: NJ Posts: 2,381 Drives: slowly Rep Power: 33858	I occasionally grind 1st to 2nd but I attribute that to lack of attention rather then the syncro because its not consistent. Pretty much happens in all my past cars. I don't see an issue skip shifting if you give the time to match revs. Last edited by 2011 Nismo#91; 08-24-2012 at 10:48 AM.

08-21-2012, 04:51 PM	#3 (permalink)
BGTV8 A True Z Fanatic Join Date: Dec 2009 Location: 03350 Australia Posts: 1,503 Drives: 09 Nissan 370Z M6 Rep Power: 29907	I now have the crunchies on skip shift from 3rd to 6th at max-revs (like accelerating the car up to speed on the on-ramp to freeway and then slot into 6th at 110kph). Car has 70,000klics on it. So far, only 6th affected. Have gone to Motul gear oil and is "better" but not perfect. I have an extended drivetrain warranty (up to 150,000 klics) on my car and will be hassling Nissan about it at the next serice, but the car has seen a lot of arduous service (track days and speed events) so I'm optimistic about a Nissan repair .. we'll see.

08-24-2012, 08:55 AM	#10 (permalink)
Red__Zed A True Z Fanatic Join Date: Jul 2010 Location: window seat Posts: 28,940 Drives: Mostly on two wheels Rep Power: 119	Well known that the Z has crappy synchros. They toughened up the 5th gear synchro in mid10 and again in early 11. By all measures the mid11s seem to have dramatically better 5th gear behavior.

08-24-2012, 10:59 AM	#12 (permalink)
SPOHN A True Z Fanatic Join Date: Feb 2010 Location: Covington, GA Age: 45 Posts: 14,844 Drives: Waiting on next Z Rep Power: 221	I'd like to know with what people have had problems do they have SRS? __________________

08-24-2012, 04:23 PM	#13 (permalink)
IDZRVIT A True Z Fanatic Join Date: May 2009 Location: Halifax Posts: 1,659 Drives: '13 CTS-V, '76 Vette Rep Power: 26	I doubt SRS has anything to with it. All its doing is revving the engine to make a smooth downshift which is a benefit if anything by reducing stress. Now if there were some mechanical linkage then there might be a cause for concern but there isn't. It's all electronic. No car is bullet proof. If you beat on it beyond its design parameters its gonna break. Open up your wallet and don't expect the warranty to cover it. __________________ "America.... still builds rockets!" Vette: 355 cid, 400 rwhp '13 CTS-V Coupe: 6.2L LSA, 556HP

08-24-2012, 06:14 PM	#14 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 42	Haha I don't beat on my car that much even with FI. I haven't even tried dumping the clutch or drag race. The summer heat has been a record breaker so I don't get to drive as hard. My car has lots of freeway mileage. Plus 5th isn't even a gear I would race in. It's just a daily driver to and from work. My tech knows I baby this car lol. __________________

08-24-2012, 08:30 PM	#15 (permalink)
Telephone Enthusiast Member Join Date: Dec 2011 Location: San Diego, CA Posts: 297 Drives: 2012 Sport M6 Rep Power: 13	Downshifting into 5th during normal driving can be a pain. It's hit or miss really. SRS is always OFF. Is this tranny used in any other Nissan/Infinity model? If so, are there other complaints?

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