Changes in 6-speed transmissions?

[CDX_NSX]

Curious. I understand that there was a change in the 6-speed transmissions used in the NSX in 2002. What was the difference between the later 6-speeds and the earlier ones?

 

[john@johnhudakracing]

Curious. I understand that there was a change in the 6-speed transmissions used in the NSX in 2002. What was the difference between the later 6-speeds and the earlier ones?

Practically, because of the teeth on the counter shaft if you have the newer post 02' A61 transmission, it is compatible with the 4.23 NA2 NSX-R final drive whereas the depricated pre-02 E61 was not. I ordered a new one awhile back and did receive the newer A61 from parts.

 

[Larry Bastanza]

Practically, because of the teeth on the counter shaft if you have the newer post 02' A61 transmission, it is compatible with the 4.23 NA2 NSX-R final drive whereas the depricated pre-02 E61 was not. I ordered a new one awhile back and did receive the newer A61 from parts.

Respectfully I have to disagree. The differential is the part that needs to be compatible with the 4.23, not the countershaft, you get a new countershaft with the kit. The Differential in the 2002 is the same for 1995-2005. Non are compatible with the 4.23.

The inner teeth on the RING GEAR for 1995-2005 are cut on an angle to help increase the lock up torque, which required the 1995-2005 differential carrier with the proper mating angled gears.

The 4.23 ring gear has straight cut inner gears to go along with the 1991-1994 original differential, that for the NSX-R is reshimmed for a higher break-away torque.

In 2000 the main change to the transmission is that the 5th and 6th gears also got dual syncros, making it ALL (6) dual syncros, and there were some other minor changes too. The A61 is the only stocked part at this time, the E61's are N/A, not that you would want one

HTH,
LarryB

 

[john@johnhudakracing]

Respectfully I have to disagree. The differential is the part that needs to be compatible with the 4.23, not the countershaft, you get a new countershaft with the kit.

Agreed. I wasn't refering to the counter shaft in the tranny, rather the one included in the 4.23 kit vendors offer.

The Differential in the 2002 is the same for 1995-2005. Non are compatible with the 4.23.

Larry, I am unclear on this point. Your statement seems to be asserting blanket incompatibility (e.g. 4.23 gears cannot be installed on a 6spd - due to the straight cut on the inner teeth on the ring gear). However, if I am reading into this right I think what you are actually inferring is that it does work but simply further parts are needed (additional parts from a 91-94 diff).

 

[Larry Bastanza]

That is correct, you must retrofit(backdate) to the 1991-94 differential carrier to install the 4.23 on ANY 6 speed.

Some incorrect info is floating around about 2002+ transmissions being compatible and this is really not the case.

HTH,
LarryB

 

[CDX_NSX]

Great info. Thanks, guys.