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Hi,

Just want to confirm that all 6 speed g/boxes in NB's are exactly the same - '99 10AE thru' to '05 ?
What about the SE ?

Cheers,
Gregg

Oh god...

Hmmm... What to say?

This is a can of worms question if ever there was one.

Dann

http://www.miata.net/garage/KnowYourCar/S8_Gears.html
Ratios are the same

http://miataroadster.com/miataroadster/miataroadster_short_shifter_kits/g-63251.aspx

2001-2002 6-SPEED OWNERS PLEASE NOTE:
We’ve determined that Mazda changed the design of the 6-speed transmission somewhere in between the 2001 and 2002 model years. So if you have a 2001-2002 6-speed, please check your VIN before ordering a shifter kit because the contents vary. If the last six digits of your VIN are below 220739, order the kit for 1999-2001. If the last six digits of your VIN are above 220738, order the kit for 2002-2005.

HISTORY OF MIATA SHIFTERS:

For NB2 6-speeds, Mazda enlarged the OD of the tip of the shaft (from 15mm to 17mm) and the ID of the hole in the turret (from 19mm to 21mm) vs. all NA/NB 5-speeds and NB1 6-speeds which share the smaller dimensions.

To complicate matters, all NB1/NB2 6-speed shafts have the same shorter distance between the axes of the fulcrum balls and tip balls vs. all NA/NB 5-speeds.

To economize on manufacturing our kits, MiataRoadster uses the same 15mm size tip on all shafts and uses proprietary thicker-walled bushings for NB2 6-speeds.

If you’re swapping a tranny, the VIN riveted onto the side of its case will confirm its source.

To the best of my knowledge, the breaking point between the NB1 and NB2 6-speeds is the VIN ending in -220738. This should apply worldwide.

Mazda:

NA/NB 5-speed
&
NB1 6-speed:
shaft tip 15mm D
turret hole 19mm D

NB2 6-speed:
shaft tip 17mm D
turret hole 21mm D

MiataRoadster:

NA/NB 5-speed
&
NB1 6-speed:
shaft tip 15mm D
turret hole 19mm D

NB2 6-speed:
shaft tip 15mm D
turret hole 21mm D

Thanks Magpie,

So it seems the only difference is in the shifter.

Therefore a 6 speed, complete with shifter, from an '04 (not SE) should fit straight into a '99 10AE ?

Cheers

RS2000 wrote:So it seems the only difference is in the shifter.

Therefore a 6 speed, complete with shifter, from an '04 (not SE) should fit straight into a '99 10AE ?

Essentially yes, the only difference with the SE gearbox from other NB8c of the same vintage was that the SE gearbox was (allegedly) stronger than the standard box with all the gears being 'shot peened' to help with the additional stress caused by the turbo engine. This is a matter of contention in many areas.......

This is why its a can of worms..


Mazda advertising documents supposedly mentioned shot peened gears in an advertisement for the SE.
However there is no evidence that this is any different for any other aisin AZ6 gearbox (the az6 is used in huge numbers of cars from s2000's to nissan silvia S15's).

Thanks,
Dann

I don't mean to sound naïve but could Mazda really lie about something like that though? Where did the shot peened info come from? Ie is it in a genuine brochure somewhere ?


Sent from my iPhone using Tapatalk

it should not come as any surprise. The Japanese companies especially Toyota embraced continuous quality improvement and there is often no need for them to signal to customers that a variation had been made. A gasket can have an updated spec or design mod which still makes it fully interchangeable. If you buy parts from Toyota or Mazda they ask for VIN so that customers get the right bits. The evidence for shot peening will be in Mazdas spec which is part of the component but none of us ever see that detail.

emily_mx5 wrote:I don't mean to sound naïve but could Mazda really lie about something like that though? Where did the shot peened info come from? Ie is it in a genuine brochure somewhere ?

Im not suggesting a lie, simply that all AZ6 may be shotpeened, but no one cares except the guy who was writing the brochure to sell the most expensive mx5 model ever sold at that time.

Dann

emily_mx5 wrote:I don't mean to sound naïve but could Mazda really lie about something like that though? Where did the shot peened info come from? Ie is it in a genuine brochure somewhere ?


Sent from my iPhone using Tapatalk

Mmm...didn't Mazda over quote power figures? Why would they lie about something like that?

They didn't really over quote them, testing standards differed between the countries and the used the rated power numbers from the wrong country (why was higher).


Sent from my iPhone using Tapatalk

Magpie wrote:http://www.miata.net/garage/KnowYourCar/S8_Gears.html
Ratios are the same

http://miataroadster.com/miataroadster/miataroadster_short_shifter_kits/g-63251.aspx

2001-2002 6-SPEED OWNERS PLEASE NOTE:
We’ve determined that Mazda changed the design of the 6-speed transmission somewhere in between the 2001 and 2002 model years. So if you have a 2001-2002 6-speed, please check your VIN before ordering a shifter kit because the contents vary. If the last six digits of your VIN are below 220739, order the kit for 1999-2001. If the last six digits of your VIN are above 220738, order the kit for 2002-2005.

HISTORY OF MIATA SHIFTERS:

For NB2 6-speeds, Mazda enlarged the OD of the tip of the shaft (from 15mm to 17mm) and the ID of the hole in the turret (from 19mm to 21mm) vs. all NA/NB 5-speeds and NB1 6-speeds which share the smaller dimensions.

To complicate matters, all NB1/NB2 6-speed shafts have the same shorter distance between the axes of the fulcrum balls and tip balls vs. all NA/NB 5-speeds.

To economize on manufacturing our kits, MiataRoadster uses the same 15mm size tip on all shafts and uses proprietary thicker-walled bushings for NB2 6-speeds.

If you’re swapping a tranny, the VIN riveted onto the side of its case will confirm its source.

To the best of my knowledge, the breaking point between the NB1 and NB2 6-speeds is the VIN ending in -220738. This should apply worldwide.

Mazda:

NA/NB 5-speed
&
NB1 6-speed:
shaft tip 15mm D
turret hole 19mm D

NB2 6-speed:
shaft tip 17mm D
turret hole 21mm D

MiataRoadster:

NA/NB 5-speed
&
NB1 6-speed:
shaft tip 15mm D
turret hole 19mm D

NB2 6-speed:
shaft tip 15mm D
turret hole 21mm D

VIN 201653 2002 NB8B
i just had my centre console off to confirm torn boots before ordering some new boots and a turrent bush.
gear lever ball end is 18mm diameter and the turrent bush is 22mm diameter.
i wonder if there are 3 sizes
still ,it doesnt really matter so far as the OP question goes.