6 Speed Final Drive Replacement

[jtrikakis]

Hi Everyone,

I have a 1991 that I replaced the 5 Speed with a 6 Speed transmission. The 6 speed was modified to use a double clutch (SOS parts where used) and it has a CompTech 4.55 final drive. I wish to replace the 4.55 with a stock 4.06 and retained the use of the double clutch. That said, what parts should purchase to make this this work besides the 4.06 gear? Thanks.

 

[Honcho]

If you have a dual clutch on the 6-speed, that means you have the NSX-R mainshaft. All you should need to replace is the ring gear, unless you go with the NSX-R 4.23 ring gear. In that case, you would need a 5-speed differential.

 

[jtrikakis]

Thank you for your response. You are correct, I have a dual clutch (not a double clutch). I learned to drive 5 and 10 Ton tractors to pull trailers that forced me to double clutch to shift gears. Glad those days are well behind me.

 

[Larry Bastanza]

If you have a dual clutch on the 6-speed, that means you have the NSX-R mainshaft. All you should need to replace is the ring gear, unless you go with the NSX-R 4.23 ring gear. In that case, you would need a 5-speed differential.

To be exactly correct you would need a 1991-1994 differential.

 

[jtrikakis]

Thanks everyone whom have responded. So I am clear on the parts I need to replace the 4.55 with a 4.06 and retain my Dual Clutch, I would need a 1991-1991 differential and 4.06 final gear. I am correct on this? - Jim Trikakis

 

[OLDMNSX]

Jim,
There is a lot more to changing the differential gear ratio besides just changing the ring and pinion. I would suggest that you get a copy of the OEM maintenance manual and read about this procedure. If you change the differential you will need to check the preload on the bearings when you put the new differential in your case halves.
This may be a job for Jeff at Science of Speed. If Jeff does it it will be done right.
Brad

 

[jtrikakis]

Thanks again. I am having a local NSX tech look into the swap on Monday. I know the previous 6 speed owner had the R shaft installed so he could retain the dual clutch. Once I find out more, I'll post an update. Thanks.