JimSUPERFLY

I received and installed ATS's mission final gear (secondary drive gear) in my 04 AP2 a few days ago.
Beautiful product, I can tell quality is top notch.

http://www.ppi-ats.com/Gears/Mission%20Final.html

I chose that route mainly because I use my S2k on the street quite a bit and the combination of highway revs with a 4.44 ratio and a loud exhaust worried me so 4.30 seemed like a good compromise.
Secondly I didn't want to screw around in the rear diff. The install of this gear is so much easier and doesn't require much experience like a diff does.
I also liked the fact that this will not make the driveshaft and diff spin any faster than they did stock compared to a diff final drive since the reduction is in the tranny.
It was also cheaper.

SCROLL DOWN FOR DIY. I SUGGEST THIS DIY SHOULD GO IN THE LIBRARY.

I will keep you guys updated on the results on the street in April and on track early May. I know, Canadian winters suck...

cujet

Nice, I'm glad such parts are available. Since you are AP2, was it only a single gear replacement, and not the shaft? How do they change the ratio without changing both gears?

I had been wondering if such gears were available. But, to change the ratio the other way. I'd like to at least a 10% reduction in engine RPM (turbo)

JimSUPERFLY

Yes it's a single gear replacement for AP2. Since there is only 1 tooth difference it works fine with the output shaft oem gear. Maybe just a difference in backslash, I'm no gear expert.

Do you have AP1 or AP2?

devildust

This is tempting, although I have an AP1 so would need to buy a secondary AP2 shaft.

cujet

I have an AP2. I wrote the ATS guys to see if it's possible to go the other way. Otherwise I'll have to change rear gears.

JimSUPERFLY

You could swap with AP1 shaft and AP1 gears and gain a few % maybe?

Gernby

I would like to go the other way too, and have considered swapping in an AP1 secondary gear set. However, it would be nice if someone would offer a gear that doesn't require swapping in the AP1 shaft. I assume the effort to swap both would be significantly higher.

2ndTimeAround

+1 on a higher (numerically lower) gear for the AP2

JimSUPERFLY

DIY coming.

JimSUPERFLY

ATS AP2 S2000 mission final gear installation DIY

If you need a DIY to change your oil this is NOT for you. I am not responsible for any problems.
Not difficult if you do most of the work on your car yourself and have the proper tools.
A shop manual for consulting and torque specs is suggested.
Special tools needed : pullers (I used 2 sizes), gear puller, 38 mm socket and a new 29mm countershaft nut from Honda:



-First put your car up on stands, high enough to be comfortable working underneath it. Or a lift if you are lucky...
-Remove transmission filler plug and oil drain plug, let it empty itself while you start in the car.
-Remove shifter knob and center console.
-Put in neutral.
-Remove rubber boot with a flat screwdriver where there are point marks on the plastic ring (stick in and pull in while pulling up on plastic ring with hook):



-Remove shifter by removing 3 bolts under another rubber boot:



-Support transmission with jack and wood bloc:



-Detach driveshaft, driveshaft support, and let it hang or completely remove drive shaft.
-Remove transmission mount bolts.
-Remove 4 bolts holding shifter dust boot to the tunnel underneath.
-Lower transmission about an inch or two for easier access of the 4 bolts holding the shifter base inside:



-Remove bolts and shifter base from underneath. There are dowel pins so you might have to lower transmission a bit more.
-Push shifter linkage forward (3rd gear) and remove bolt and bracket:



-Pull shifter linkage back to neutral with a screwdriver, the driveshaft flange should rotate freely underneath.

-Loosen transmission end cover bolts in a cross pattern.
-Completely remove them, push O2 sensor wire brackets back out of the way.
-Use a pry bar or large flat screwdriver and detach transmission cover slightly, breaking the gasket seal.
-Pull gently to remove cover, be careful for lower pump gear not to fall. Remove oil pump gear. You should end up with this (oil pump gear removed):





-"Un-stake" the 29mm nut (I used a chisel and a hammer):



-Put in 1st gear and lock front crank pulley bolt with a ratchet:





-Remove 29mm countershaft nut (CLOCKWISE!!!) with a long ratchet.
-Remove spring washer.
-Install bearing puller:



-Pull bearing off:



-Pull gear off:



-Align ATS gear and tap in (I used a large socket and hammer). You will feel it when it's all the way in, confirm with pump gear alignment on small sprocket:



-Align bearing and tap in:



-Reinstall spring washer conic side up.
-Lock front crank pulley bolt the opposite way.
-Install new 29mm nut COUNTER-CLOCKWISE, torque to 127 ft/pnds, stake the nut.
-Clean surfaces from oem gasket sealer with a razor blade and solvent (brake cleaner), do not scratch.
-Put transmission in neutral.
-Reinstall pump shaft and gear.
-Put gasket sealer and realign cover with dowel pins, push in.
-Reinstall bolts, the 2 long ones go where the dowel pins are.
-Tighten gently in a cross pattern and torque to 20 ft/pnds in a cross pattern.

-Reassemble rest in reverse order of disassembly. Grease shifter pivot and base, torque shifter rod bracket bolt to 30 ft/pnds.

-Have a beer.