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Nsx Transmission w/JDM Short Gears and 4.23 NSXR Final Drive installed

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23 January 2011
Washington D.C.
Don't miss out on this chance at the best Performance Upgrade for your NA NSX
1992 Acura/Honda NSX 5 speed Transmission with Full NSXR UpGrades

Removed from my USDM 1992 Acura NSX

Transmission has the NSXR JDM 2,3,4 short gears installed and NSXR 4.23 Final Drive Kit with Upgraded Differential spring.

Paid close to $3500 in parts

New input and counter shaft bearing installed as well.


Retail SOS $1315.75

Japanese and European 5-speed NSX are equipped with a gearset that offers tighter 2-4 gear ratios. The US gearset results in shift points in the lower gears that places the resulting engine speed below the optimal power point. The JDM short gears allow better acceleration especially noticeable in the shift between 1st and 2nd as the engine does not fall out of the useable powerband. The JDM Short Gearset includes all parts to retrofit your US-spec gearbox. This modification results in faster acceleration times. Excellent in combination with the NSX-R 4.23.

The kits include the mainshaft and gears for the counter and mainshaft.

DESCRIPTION of Final Drive

Retail at SOS $1720.75

In Japan, a special performance tuned version of the NSX is available. The NSX-R model includes a higher ratio final drive gearset that increases the normal NSX 4.062:1 ratio to 4.235:1. This modification results in noticeably faster acceleration times.

In addition to the NSX-R final drive (countershaft, ring gear, and oil gear), this kit also includes the NSX-R stopper plate and spring plate. The stopper plate & spring plate increase LSD lock up rate and breakaway torque.

DESCRIPTION of Spring Plate

Retail at SOS $130 (not including install)

Differential conversion kit includes NSX-R stopper plate and spring plate. This allows any 5-spd NSX LSD to be converted to NSX-R specification. The stopper plate increases LSD lock up rate and the spring plate, used in conjunction with the existing spring plate, allows increased breakaway torque. The result is better corner traction, especially when used with high-performance tires.

Installation of all items requires the dismantling of the transmission main and counter shafts and differential.

Gears and final drive where installed in my nsx about 7 years ago. Has about 15k miles since install. Shifts beautifully, no grinds. The transmission case did have a hairline crack welded in the bell housing. The Science of speed clutch pressure plate lost a damper spring and flung around in the case on its way out. The hairline crack did not effect the functionality or structural rigidity of the case. Pics below

Only reason I’m selling is I recently purchased a 6 speed transmission and this must go to pay for it.

Price:$4300 plus PayPal fee and shipping

Transmission includes everything pictured release fork and all.
I will post new pictures after I get a chance to clean it.

Any questions just ask!

Thank you



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Very interesting.

What kind of gas mileage did you get with these short gears and final drive?
Very interesting.

What kind of gas mileage did you get with these short gears and final drive?

there is a noticeable difference, quicker acceleration and hwy speed RPM is higher.
But compared to a USDM trans it’s night and day. The 1-2 shift is perfect
My nsx has been turboed for about 6 years now so I don’t know true MPG’s

but the performance gain far beats out the mpg sacrifice
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