Short gears/final drive 4.23 installation PICS (56k warning!)

[goldNSX]

Deylo and me tried to do the mission impossible (to us ) of installing the short gears and final drive 4.23 into his NSX between christmas and newyear. Actually I was only assistant and I let do the other guys (deylo and Mr. Amacher) do the job.

This car is well known:

<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6389.JPG" border="0" />
<br/>

 

[jeffchai]

WOW sexy! too bad i have no use for my comptech ring and pion any more or else i would of swap it in.

 

[goldNSX]

I wasn't present during the dismounting of the gearbox but as you can see it's quite a lot of steps to follow. Working step by step through the SM was the thing to do. After that quite a lot of parts are missing:

<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6353.JPG" border="0" /> <br />
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6356.JPG" border="0" /> <br />
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6350.JPG" border="0" /> <br />
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6393.JPG" border="0" /> <br />

For most of the work we're using a big hammer, ok, just to hold the engine in place.
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6392.JPG" border="0" /> <br />

 

[goldNSX]

Also recognised:

Clutch:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6344.JPG" border="0" /> <br />

Leaking cam seal:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6342.JPG" border="0" /> <br />

 

[goldNSX]

Now it's here where my stuff begins: Dismounting of the gearbox (done by Beat).

Tranny case:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6348.JPG" border="0" /> <br />

and cover:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6347.JPG" border="0" /> <br />

Cleaner is better:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6357.JPG" border="0" /> <br />

 

[goldNSX]

Disassembling of the differential, the SM pages always open, doing step by step.

<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6359.JPG" border="0" /> <br />

Differential gears:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6363.JPG" border="0" /> <br />

Old preloading spring and plate:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6366.JPG" border="0" /> <br />

New spring and plate, BINGO one shime missing
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6367.JPG" border="0" /> <br />

So we've tried to get it worked but the shime was essential for the NSX-R preloaded differential. Facing this we went the save way and didn't install it.

Reassembling and putting back in the tranny case: differential with 4.23 ring and matching oil pump gear:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6369.JPG" border="0" /> <br />

 

[goldNSX]

Going over to the countershaft:

After loosing 20 minutes before finding out that the locknut has left-hand threads:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6371.JPG" border="0" /> <br />

Thanks to the manual:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6372.JPG" border="0" /> <br />

Using the press (max 1000 kg!)
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6373.JPG" border="0" /> <br />

with the new parts waiting in line. We did two parallel lines, one with the dismounted parts and one with the parts to be installed:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6375.JPG" border="0" /> <br />

All synchros looked perfect, not bad for a gearbox with 50k miles:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6376.JPG" border="0" /> <br />

 

[collegeboy]

Great to see some people DIYing stuff. Good job. Car looks great.

 

[goldNSX]

Next step: mainshaft:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6378.JPG" border="0" /> <br />
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6379.JPG" border="0" /> <br />
Completed:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6380.JPG" border="0" /> <br />

 

[goldNSX]

One thing to mention: All parts in the gearbox have been in excellent condition, EXCEPT for one: The top countershaft bearing that sits next to the snapring. According to Michael and Marek of Germany which had a failure of exactly this bearing this is the weak point of the hole gearbox. Thanks! So we've changed it anyway. Good to know we did the right thing.

Countershaft top bearing on the left:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6383.JPG" border="0" /> <br />

 

[goldNSX]

On we go with the reassembling of all the stuff in the gearbox:

<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6384.JPG" border="0" /> <br />
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6387.JPG" border="0" /> <br />

Finished gearbox ready for install. Seems easy to get to this point but isn't actually. First the shift arms need to be pushed inside by a assistant to get the cover completely on the tranny case. Second the shift knuckle needs to be in a certain position (the SM talks about that). While you lower the cover an assistant needs to check if the shift knuckle is inside the shift arm. First we didn't have it this way. A second try and the SM helped us over this.
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6404.JPG" border="0" /> <br />
There was one problem with a gearbox bolt. We fixed that by cutting new threads.
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6405.JPG" border="0" /> <br />

 

[Prospeed]

Excellent write up. Keep up the good work! From the looks of the jacket and beanie it must be freezing in Switzerland! hehe :smile:

 

[goldNSX]

For the next 2 hours I didn't do any photographs, first because I was busy, second none of us (3 people) couldn't stand any pictures because reinstalling the tranny was a PITA. Two guys were balancing the gearbox to the clutch/tranny, one was turning the engine to make sure the mainshaft threads matched the clutch discs. After that we've lost another hour because the shifting mechanism inside the clutch housing was not in the correct position preventing the tranny to be sucked to the engine.
You're working under the car and from the top:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6409.JPG" border="0" /> <br />

 

[goldNSX]

We were late anyway and found another problem where your input is very welcome.

HOW DO YOU INSTALL THE RIGHT DRIVE SHAFT if the tranny is already in position?

We've tried several things, mainly pushing the drive shaft in the tranny first but there was always the engine block in the way of the part that holds the drive shaft to the tranny. The SM says nothing about it.

Right half drive shaft (separated)
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6413.JPG" border="0" /> <br />

and the problem zone:
<img src="http://www.honda-nsx.ch/images/2007_12_28/IMG_6414.JPG" border="0" /> <br />

 

[goldNSX]

Unfortunately we had to stop working for this day and I won't be present while the rest is installed. Deylo has about 4 hours to go before he gets what he worked for. The pain took a long time, yes, but the relief (short gears/4.23) will last MUCH longer. :wink:

He also mentioned that this is was the last thing we did and never do it a second time. Reason? My answer: Now we know how to do it! So watch out as soon as my car needs new head gaskets (plus timing belt). Then we take out the hole engine/gearbox/suspension-thingy. :tongue:

Warning: This is not a project for beginners!

Special and big thanks to http://www.amsportcars.ch/web/index.html which was a pleasure to work with.

 

[goldNSX]

Excellent write up. Keep up the good work! From the looks of the jacket and beanie it must be freezing in Switzerland! hehe :smile:

As I was the photographer there are no pics of me. IF you would have seen me (I was dressed like an Eskimo) you could imagine that is was about 0 to 5 degrees Celsius in the place we worked. :eek!: I hope my caught won't last very long...
It was -7 degrees outside.

 

[menfou]

Beau boulot,

J'ai eu le meme probleme que toi aujourd'hui, j'ai meulé un peu l'arbre intermédiare au niveau du vis du dessus pour qu'il passe.
Il faut juste enlever un peu de matiere et tu n'auras pas de soucis pour remettre l'arbre, sinon tu es bon pour redémonter ta boite.
J'ai mis 8h pour tomber la boite, changer l'embrayage et remettre la boite, on était 2 dessus.
Demain je tombe le réservoir pour monter ma pompe Walbroo

 

[jeffchai]

great job! hope u get the beast running soon.

 

[Speedy_Bamberg]

Hello Thomas,

very nice work!

Welcome in the club of countershaft bearing changer!!!

The countershaft bearing is really the weak point of the hole gearbox! :frown:

Here is my Story http://www.hondansx.de/phpBB/phpBB2/viewtopic.php?t=108

greeting Marek!

 

[sivernsx]

I am impressed with the workmanship.
I myself like to do this type of project. well, not me physicaly. I recently just finished my turbo kit.
My mechanic is trying to persuade to do the short gears.
He's proven to me the gears between 1st and 2nd is to spread apart. My boost drops. little lag.
I have a 92. I dont want to loose anything up top. You seem pretty knowledgeable. I am pretty sure you did your homework before tackling this project. what would you consider. short gears or 6speed conversion.

 

[goldNSX]

I have a 92. I dont want to loose anything up top. You seem pretty knowledgeable. I am pretty sure you did your homework before tackling this project. what would you consider. short gears or 6speed conversion.

Thanks for the compliment. We did a wide and deep analysis what would fit our needs. This helped much.

As you have plenty of power with the Turbo, I'd go for the short gears WITHOUT FD 4.23 and the spread between 1st and 2nd is gone. 6sp is simply not worth it IMO. Above 100 mph, the 6sp is slighty faster as you have one more gear between 4th and 5th. But the long 6th is not very good at top speed IMO.

 

[NetViper]

Nook, I would go with the 6-speed and 6.23 if I were you. The short gears and 4.23 is ok, but IMO you cannot beat the 6-speed. Crusing on the hiway at 80MPH sucks with the short gears and 4.55 (though i havent been in 4.23). The engine is spinning nearly 4000 RPM and its too loud.

Charles Husdon has a 6-speed swap in a 92 and it is PERECT.

 

[goldNSX]

Announcement: Get prepaired for the full photo story of the engine out/TB/Cam seals and more by the end of march!