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Old 02-06-2007, 12:56 PM
  #81  
Wired 24/7
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OK guys I took the off-topic comments and moved them. Please don't b1tch about it, I am not trying to censor anyone's opinions.

If you want to continue the discussion about race trannies / non-350Z-6MT trannies, then go for it.

https://my350z.com/forum/forced-induction/247740-discussion-of-transmissions-spinoff-of-sticky-with-6mt-pics.html
Old 02-06-2007, 01:43 PM
  #82  
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Brian, the issue I see with the trans, is the VERY sluggish shifting under heavy load...550whp+, and 7000rpm+. Can you ask your trans guy, if this issue can be fixed? This is what seperates the Supra and Viper transmissions from the 350z, IMHO. Strength and size of gears is one piece of the puzzle, but the shift forks, synchros and blocking plates are another piece I would like to understand. How can we make our trans shift better without locking out, or grinding under very heavy load. In 4th gear, I cannot shift to 5th at 7500rpm....just wont go into gear, so I am forced to shift into 5th at about 7000rpm max.
Clutch issues (like the following) sometimes cause slow or difficult high rpm shifts:

1. Clutch adjustment not allowing full release.
2. Pressure plates that increase grip based on rpm (Centerforce style).
3. Linkage components distorting at higher pressures/rpms.
4. Clutches that are heavy or OEM style with center springs.

As rpms go up, multi-disc clutches with small ODs and annular clutch release mechanisms make more sense.
Old 02-07-2007, 12:25 AM
  #83  
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Anyone?

Originally Posted by DRE350
I need help/advice. I have an 03 Z Coupe and an 05 ZR. I'm selling the ZR and turning the 03 into a circuit/track car and I am contemplating swapping the gearboxes.

The 03 gearbox shifts very smoothly and the 05 box sometimes grinds going into 2nd and sometimes has trouble getting into 1st from a standstill.

My question is would you take the 03 or 05 box keeping in mind the 05 had revisions like double and triple syncros?

Am I right in assuming that the newer gearbox which has all the upgraded revisions should be stronger.

Thanks.
Old 02-07-2007, 03:19 AM
  #84  
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Can you speak with your shop about possibly synchro options? That is something I would be definitely interested in.

-Acree
Old 02-07-2007, 05:06 AM
  #85  
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Originally Posted by Acree
Can you speak with your shop about possibly synchro options? That is something I would be definitely interested in.

-Acree
Not really sure what you mean. The only real "option" with the synchros would be to update the parts to the latest revision's specifications. Other than that you get into VERY expensive custom work.
Old 02-07-2007, 09:06 AM
  #86  
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Originally Posted by BriGuyMax
Not really sure what you mean. The only real "option" with the synchros would be to update the parts to the latest revision's specifications. Other than that you get into VERY expensive custom work.
I'm not quite sure how it all works, but I just figured there was some way to improve the general feel and behavior of the shifter.

-Acree
Old 02-07-2007, 09:26 AM
  #87  
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Originally Posted by Acree
I'm not quite sure how it all works, but I just figured there was some way to improve the general feel and behavior of the shifter.

-Acree
I'm just going to order new syncros, shift forks and have them installed with my motor build. Told by Infiniti tech, it's the best way to solve some of the issues. Around $400 for the parts from Grubbs Infiniti/TX + plus less labor with the motor out.
Old 02-07-2007, 11:02 AM
  #88  
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Originally Posted by Acree
I'm not quite sure how it all works, but I just figured there was some way to improve the general feel and behavior of the shifter.

-Acree
Shift feel and behavior isn't really a function of the synchronizers alone. It's a function of the combined cohesiveness of the shift linkage, rods, detent ***** and springs, shift forks, fluid AND the synchronizers.

If you don't like the way your transmission shifts, the first thing I'd address is fluid. That is assuming that you don't have grinding issues under normal shifting conditions.
Old 02-07-2007, 11:04 AM
  #89  
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Originally Posted by BrianLG35C
I'm just going to order new syncros, shift forks and have them installed with my motor build. Told by Infiniti tech, it's the best way to solve some of the issues. Around $400 for the parts from Grubbs Infiniti/TX + plus less labor with the motor out.
Make sure some one who has a decent amount of experience inside a manual transmission is doing the work on your trans. A normal tech at a performance shop that's used to bolting on exhausts and suspensions shouldn't be cracking open the 6MT.
Old 02-07-2007, 11:17 AM
  #90  
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Originally Posted by BriGuyMax
Make sure some one who has a decent amount of experience inside a manual transmission is doing the work on your trans. A normal tech at a performance shop that's used to bolting on exhausts and suspensions shouldn't be cracking open the 6MT.
Pm'd you.
Old 02-07-2007, 12:41 PM
  #91  
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Originally Posted by BriGuyMax
Shift feel and behavior isn't really a function of the synchronizers alone. It's a function of the combined cohesiveness of the shift linkage, rods, detent ***** and springs, shift forks, fluid AND the synchronizers.

If you don't like the way your transmission shifts, the first thing I'd address is fluid. That is assuming that you don't have grinding issues under normal shifting conditions.
I addressed this when the current transmission was put into my car. It's an 008 build and no issues with it so far. Over 9k on it too. After I drove the car for 1000 miles, I changed the fluid out for the redline stuff. It mad it alot better, but to me it's still notchy. My main concern is I need a transmission that I can beat the hell out of, and it will still hold up.

-Acree
Old 02-07-2007, 01:28 PM
  #92  
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Originally Posted by betamotorsports
Clutch issues (like the following) sometimes cause slow or difficult high rpm shifts:

1. Clutch adjustment not allowing full release.
2. Pressure plates that increase grip based on rpm (Centerforce style).
3. Linkage components distorting at higher pressures/rpms.
4. Clutches that are heavy or OEM style with center springs.

As rpms go up, multi-disc clutches with small ODs and annular clutch release mechanisms make more sense.
We agree, it is most likely more a clutch issue than an actual tranny issue causing failure.
Old 02-07-2007, 03:56 PM
  #93  
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Originally Posted by betamotorsports
Clutch issues (like the following) sometimes cause slow or difficult high rpm shifts:

1. Clutch adjustment not allowing full release.
2. Pressure plates that increase grip based on rpm (Centerforce style).
3. Linkage components distorting at higher pressures/rpms.
4. Clutches that are heavy or OEM style with center springs.

As rpms go up, multi-disc clutches with small ODs and annular clutch release mechanisms make more sense.
That's a possible cause of the issue. However, my trans shifts nicely at 7500rpm in gears 1-3, but 4th is a little rough, and 5th is impossoble at 7500rpm. At 7000rpm or less, all gears shift smoothly.
I am using a super light Carbonetics triple disc carbon with 8 inch discs...so interia is not an issue with my setup. Still wanting to learn more about BriGuy's trans guy uncovers.
Old 02-07-2007, 03:58 PM
  #94  
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Originally Posted by Nealoc187

To clarify something regarding the sychronizers according to the FSM:

Revisions 000 through 004:
1st: double synchro
2nd: double synchro
3rd: single synchro
4th: single synchro
5th: single synchro
6th: single synchro

Revision 005 through 008:
1st: double synchro
2nd: triple synchro
3rd: double synchro
4th: double synchro
5th: single synchro
6th: single synchro

Revision 009 (if there's a higher revision than this I haven't seen data on it):
1st: triple synchro
2nd: triple synchro
3rd: triple synchro

4th: double synchro
5th: single synchro
6th: single synchro
Excellent post-good info I have never read on the forums! Nice to know I have 3 synchros for 3rd now waiting to be destroyed
Old 02-07-2007, 08:18 PM
  #95  
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Originally Posted by Acree
I addressed this when the current transmission was put into my car. It's an 008 build and no issues with it so far. Over 9k on it too. After I drove the car for 1000 miles, I changed the fluid out for the redline stuff. It mad it alot better, but to me it's still notchy. My main concern is I need a transmission that I can beat the hell out of, and it will still hold up.

-Acree
When you say "notchy", what do you mean? Some people confuse notchy with a good positive engagement since most manual trans cars out there have rather undefined gates and a overall sloppy shifting action which people mistake as "smooth".

I don't think the trans holding up to a beating should be something you worry about after seeing the internals.
Old 02-07-2007, 10:48 PM
  #96  
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Originally Posted by BriGuyMax
When you say "notchy", what do you mean? Some people confuse notchy with a good positive engagement since most manual trans cars out there have rather undefined gates and a overall sloppy shifting action which people mistake as "smooth".

I don't think the trans holding up to a beating should be something you worry about after seeing the internals.
I define notchy as "applying excessive force" to get it to go into gear. It could very easily take little effort, and still give great feedback as to being in gear or not.

-Acree
Old 02-08-2007, 07:02 AM
  #97  
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Originally Posted by Acree
I define notchy as "applying excessive force" to get it to go into gear. It could very easily take little effort, and still give great feedback as to being in gear or not.

-Acree
Hmm...I guess that's were we differ. I like the fact that I have to muscle it a little from gear to gear. Then again I HATE BMW shifters..which a lot of people love.

The effort required to get into gear is actually due to the very short lever length of the shifter itself, and has nothing to really do with the inside of the transmission. The only way to reduce effort would be to install a taller shifter.

A good example of this is my 2006 Frontier 6MT that shares it's transmission with our 350Z. It has a long truck shifter obviously and it takes nearly no effort to get into gear..but I don't enjoy that shifter nearly as much as the Z's...
Old 02-08-2007, 09:39 AM
  #98  
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Originally Posted by Acree
I define notchy as "applying excessive force" to get it to go into gear. It could very easily take little effort, and still give great feedback as to being in gear or not.

-Acree
Actually I would say I often experienced "lock out" of gear, where it felt as if the shifter would break off in my hand if I used any more force..
Old 02-08-2007, 11:06 AM
  #99  
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I've experienced that, but not with my current transmission. Either way, grats on the new tranny parts!

-Acree
Old 04-04-2007, 11:42 PM
  #100  
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is the revision number stamped on the transmission? if so, where?


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