Using cable 4th gear in a hydro trans. A lot of guys are using the zc 3/4 gearset in their 92-00 trans. For the most part, this is a straight forward swap, HOWEVER. Modification IS required to the inside of the cable 4th gear to use it has a hydro 4th. If you do not do this, your 4th gear will grind horribly.

You MUST modify the zc hydro 4th gear. This is the inside of a cable 4th gear:


here is a cable 3rd gear:



The inside of a cable 3rd gear is like the inside of a hydro 4th gear. Notice the orientation of the 88-91 synchro hub in comparison to the 92-00 synchro hub. For whatever reason, honda flipped it over.

Ironically, you would think that using a hydro 3rd gear as a hydro 4th gear would require the same modification that using a cable 4th gear as a hydro 4th gear. But take a look at that slightly machine vx 3rd of 1.0666 that mista bone did for me. Using a hydro 3rd as 4th gear requires no modification***




Here's a picture that s18 from d-series.org made, thanks stephan!


*** I have also come to realize that a hydro 3rd gear is SLIGHTLY taller than 4th gear. I forget the dimensions. But what happens is when you get the transmission running, the 4th gear actually "machines" the 4/5 collar. On my trans it blued the collar from the heat. Aside from the appearance this seems to have no adverse effect. The shavings from the collar will get caught by the transmission magnet. If you'd like, you can change transfluid after 100 miles. I will try to document the height difference between these gears.


If you wanna get REAL in depth here, see below.

Mainshaft comparison

on the cable 88-91 D trans
91106-PL3-008 BEARING, NEEDLE (34X39X23) (3rd gear)
91107-PL3-018 BEARING, NEEDLE (34X39X27.5) (4th gear)
23915-PL3-010 COLLAR, DISTANCE (27X34X32X55)
91108-PL3-008 BEARING, NEEDLE (32X37X23.5) (NTN CORP. (5th gear)


hydro (92-00)
91107-PL3-018 BEARING, NEEDLE (34X39X27.5) (3rd gear) (same as cable 4th)
91106-PL3-008 BEARING, NEEDLE (34X39X23) (4th gear) (same as cable 3rd)
23915-P20-000 COLLAR, DISTANCE (27X34X32X50.4)
91108-PL3-008 BEARING, NEEDLE (32X37X23.5) (NTN CORP.) (5th gear) (same as cable 5th)

the hydro has a distance collar of 4.6mm longer
needle bearing for 4th gear on hydro is 4.5mm shorter

hydro 3rd needle bearing is same as cable 4th
cable 3rd needle bearing is same as hydro 4th

The dimensions in the honda parts catalog tell us most of the difference in the mainshaft. However, there is a difference in 2nd gear. On the hydro trans, 2nd gear is 2mm "taller" than on the cable trans.

Countershaft comparison

hydro
91104-P20-008 BEARING, NEEDLE (36X41X25.5) (1st gear)
23421-P20-A00 GEAR, COUNTERSHAFT LOW (1st gear)
23912-P20-010 COLLAR, DISTANCE (33X39X32) (2nd gear)
91105-P20-008 BEARING, NEEDLE (39X44X27) (2nd gear)


cable
91104-PL3-018 BEARING, NEEDLE (36X41X24) (1st gear)
23421-PL3-010 GEAR, COUNTERSHAFT LOW (1st gear)
23912-PL3-000 COLLAR, DISTANCE (33X39X30) (2nd gear)
91105-PL3-018 BEARING, NEEDLE (39X44X25) (2nd gear)


hydro 1st needle bearing is 1.5mm taller
hydro 2nd distance collar is 2mm taller than cable
hydro 2nd needle bearing is 2mm taller than cable


And that's not even touching the differences in the fork assemblies. I haven't had time to measure the difference. After I get everything else complete on my car I then plan on going back on experimenting with the cable guts in the hydro trans.

But nevertheless if you wanna figure it out, then here's the part numbers for the fork assemblies to give you a good idea of the differences.

Hydro z6
##############################
24261-P20-000 SHAFT, SHIFT FORK (1-2)
24220-P20-010 FORK, SHIFT (1-2)

24210-P20-A00 FORK, GEARSHIFT (3-4)

24200-PL3-010 FORK, FIFTH GEARSHIFT
24271-P20-000 SHAFT, SHIFT FORK (5-R)

24243-P20-000 PIECE, FIFTH & REVERSE SHIFT

##############################
Cable a6
##############################
24220-PL3-601 FORK, GEARSHIFT (1-2)
24261-PL3-010 SHAFT, SHIFT FORK (1-2)
24261-PL3-600 SHAFT, SHIFT FORK (1-2)

24210-PL3-601 FORK, GEARSHIFT (3-4)

24200-PL3-010 FORK, FIFTH GEARSHIFT
24271-PL3-010 SHAFT, SHIFT FORK (5-R)

24243-PL3-010 PIECE, FIFTH & REVERSE SHIFT


I believe that's all for today. I'm about to really start cracking down on my F/H2D swap. Although it's an F20B it's technically an F series, but it's more like an H22 because of the DOHC VTEC head.

Another thing that I've been thinking about, creating a build thread on honda-tech or some site to document my build. Well I'm not really just working on the f/h2d swap. I'm working on a lot of other things. I don't have a build thread, because there's too much to put in a thread. My last d16b5 project thread got way out of hand and grew to be 34 pages (25 posts per page) over 825 posts in that thread.

This journal is like my build thread, although I don't have a particular build that I am working on. I am a builder, a grown up lego lover that's fascinated in how things work. I'm not a "transmission guy" I'm not a F/H2D swap guy. I'm just into this stuff and I'm along for the +ride+ wherever it takes me. If it's building transmissions, then so be it. If it's fabricating exhaust systems/mainfolds/mounts/etc then so be it. If it's building engines, oh well. If it's writing fuel/igniton maps, whatever it takes to +fuel+ my passion.

WORD


So I ain't buggin or delirious
My swift tongue's like a sword, that's how severe it is
And I can slice and dice a Fisher Price MC
that thought he was nice into Minute Rice
Single-handed, I ain't with that band stuff
Cause Cee'll scratch a record like flakes of dandruff
And the mic I ravage, not like a savage
but in my own way of doin damage
As I design the genuine line
Now whose flattop rules in eighty-nine?
-Big Daddy Kane - Warm It Up Kane

And as always, correct me if I'm wrong, I want nothing more than to have correct and accurate information posted up here. It's nothing personal.