[SEVEN]

Hello everybody !

I'm actually working on my spare gearbox, and it's nearly finished !

It's specifications:


D2L5(original)
.1st:3.307 (43/13)
2nd:1.772 (39/22)
3rd:1.230 (32/26)
4th:0.966 (29/30)
5th:0.8125 (26/32)
Rev: 3.0
FD: 4.062 (16/65)




.D2L5(modified)
1st:3.307 (43/13)
2nd:1.772 (39/22)
3rd:1.259 (34/27)
4th:0.966 (29/30)
5th:0.757 (25/33)
Rev: 3.0
FD: 4.266 (15/64)



The third speed is comming from a D2J5 gearbox, the countershaft , the final drive and the fith speed are from an H2C4 (accord CB7), and i also add an helical differential comming from an DC2 integra.

I was in part inspired by the topic

http://www.preludepower.com/forums/showthread.php?t=356224&highlight=gearbox


I can actually say that european 3rd gen Prelude are equiped with 2 "generations" of gearbox, and the most recent is really close of the gearbox that are mounted on next Prelude (4th et 5th gen), you can also use countershaft et FD from " Mfactory" if you want to shorten more, but only in the most recent 3rd gen prelude gearbox.

The only major modification i had to do is to adapt one of the countershaft bearing, that is a little bigger on the H2C4 than the original D2L5...


Some pics:

 

[SEVEN]

edit: direct links to pics and added pics :spinface:

 

[Mahusay3g]

It all looks the same to me.

What's the reason for choosing shorter gears? Our gearboxes are already close ratio.

 

[88SE Lude]

It all looks the same to me.

What's the reason for choosing shorter gears? Our gearboxes are already close ratio.

They may appear close to you lot with long straight roads to contend with all the time.
For us Eurofolk they are quite long when navigating the smaller winding back roads.
Also on track I only ever use 5th gear at one circuit where I can get up to 130mph+.



Seven, hope you've checked all the clearances on the diff and casing.

 

[007Pilon]

Nice work!

So did you machine the case bigger for the bigger countershaft bearing?

I just finished up something similar, with D2A4 as the original transmission, and H22 (M2Y4) 2nd 3rd and 4th gears. Also installed an LSD at the same time

My ratios ended up being:

Original:

D2A4 M2Y4
1-3.307 3.307
2-1.809 1.956
3-1.230 1.344
4-0.903 1.034
5-0.757 .757
F/D-4.26 4.26

I actually used the entire mainshaft, 2nd,3rd, and 4th from the M2Y4 with my original countershaft but I had a lot of trouble making everything fit. The 3rd/4th gear stack in the H22 trans is bigger than the D2a4 or accord stuff which causes problems in the prelude case.

The only way I was able to get the clearance required was to modify the bearing, so I'm not sure how well everything will work out long term but I have spare parts lol

Next time I'm planning on finding an H23 trans to use, they still have good ratios with the same size gears as the prelude/accord.

 

[SEVEN]

88seLude: yes, i've checked all the clearances of the shafts, and the preload of the differential bearings.
I only have the clearance of the mainshaft in the casing to control before to close the gearbox :-D

The problem is that the only technicals data that i have are from the 4th gen prelude workshop...


007Pilon:

Yes, exactly, i've machined the "clutch side" case in way to install a bigger roller bearing, because the original bearing is 62mm diameter, and the bearing from the H2C4 gearbox size 65mm ( the D2L5 countershaft size 33mm, the H2C4 countershaft size 38mm ) .

Is there a big difference between H22 and H23 gears size? I hope your gearbox will support the modification :-D
What do you exactly modified at the bearing?


The only difference i've noticed between lude D2L5 gears and accord H2C4 gears is between the fith gears : the 5th gear on the countershaft is a little more thick, and to use it on a 3rd gen countershaft, you have to machined it in way to make it a little thiner... :-D



(i sincerely hope i'm understandable, because my english is very poor and rusted :smilejap: )



Thanks a lot for the support and reading, it's not easy for me to share these technicals stuffs, i sincerely hope that it may be usefull for the Prelude world...

 

[cudaboy]

Thanks for the pics and sharing.

 

[SEVEN]

Thank you Cudaboy :smilejap:


007Pilon: I've read once again your answer and i think i've passed through something important for you.

I believe that your gearboxis maybe from the "old" generation and it will be a 100% time more easyier for you to use a more recent gearbox.
I'm sorry,i don't know the tranny code of the us market 3rd gen lude, i cans only talk about eudm market...

Here in France, the BA4 comes with 3 different gearboxes: D2J5 (1988) , D2L5 "old generation" (1989) and D2L5 "new generation" (1990-1991).

I was able to compare a D2J5 and a D2L5 "new gen" and these 2 gearboxes haven't the same capacity to receive H2C4 parts...
Also, D2J5 mainshaft cannot receive the 4th gear, because of a difference of the "inside" diameter... (i don't find any word more clear, i'll try to makenews pics).

In that case, i believe that you should maybe try to use a more recent gearbox, those who uses 220mm diameter clutch...

 

[007Pilon]

Thanks SEVEN

Lucky for me, D2A4 is the "newer" version trans. for north america. the same as your D2L5 I believe.

Our old version is also "D2J5" and "DJ23" etc.

The H22 gears are bigger in diameter and thickness, I'm assuming this is to give a larger area for the synchros. Because of this, hubs are thicker and the entire mainshaft is "longer"

3/4 Hub difference:




Shift forks, you can see the 3/4 fork is thicker



To make it fit, the only way I could get enough clearance was to make the mainshaft end bearing slightly thinner. I used a surface grinder to carefully remove about .030" or .040" from the original bearing as a test.

I re-used my original countershaft (already had a 4.26 final drive in the D2A4) because of the difference in bearing diameter but I had a hard time getting it to seat.

I haven't driven it much since I put the transmission together, but I'm getting a whine...

I think I might try boring the case out for the bigger countershaft bearing and using the H22 counter and final drive!

 

[SEVEN]

Thanks a lot, these informations are very interesting :smilejap:

I've got a question : do the mainshaft gears from the m2Y4 gearbox mount on your D2A4 mainshaft?

I understand that the d2A4 mainshaft is a little shorter than the M2Y4 mainshaft, but maybe you can compensate by using the fith gear from d2Y4 (if it is thinner than the one from M2Y4).

Another way of reflection, our eudm D2L5 got a 5th gear very interesting: 0.8125, that is shorter than your M2Y4 fith gear, if our D2L5 fith gear is thinner than M2Y4 fith gear, and if all that parts are mountable on the D2Y4 mainshaft, it maybe a very interesting solution for you :wink3:


It very intersting for me to know that the M2Y4 gears got a bigger diameter and are difficult to be mounted in the Third gen lude gearbox , thanks a lot for the pictures and the explanations !!!

It maybe not a so bad solution to grind a little bit the bearing, i suppose you tried to use a thinner "mainshaft thrust shim" ???


Maybe on day i will have enough time and money to try this "conversion" by myself, once again, thanks a lot!!!

 

[xkjnboix]

the 90 Si gearbox is crazy short. i couldnt imagine shorter....

 

[SEVEN]

the eudm gearbox have a "long" final drive, that is not very interesting if you want to have fun on european roads...
Also, if you want to go on tracks, it's not very efficient.:smile2:

My goal is to have nearly the same fith speed, but with the others speed a little bit shorter, in way to have a more reactive engine !

Later, i will try to have all the 5 speeds very short, in way to have a "special track gearbox" :smile2:

 

[007Pilon]

Thanks a lot, these informations are very interesting :smilejap:

I've got a question : do the mainshaft gears from the m2Y4 gearbox mount on your D2A4 mainshaft?

I understand that the d2A4 mainshaft is a little shorter than the M2Y4 mainshaft, but maybe you can compensate by using the fith gear from d2Y4 (if it is thinner than the one from M2Y4).

Another way of reflection, our eudm D2L5 got a 5th gear very interesting: 0.8125, that is shorter than your M2Y4 fith gear, if our D2L5 fith gear is thinner than M2Y4 fith gear, and if all that parts are mountable on the D2Y4 mainshaft, it maybe a very interesting solution for you :wink3:


It very intersting for me to know that the M2Y4 gears got a bigger diameter and are difficult to be mounted in the Third gen lude gearbox , thanks a lot for the pictures and the explanations !!!

It maybe not a so bad solution to grind a little bit the bearing, i suppose you tried to use a thinner "mainshaft thrust shim" ???


Maybe on day i will have enough time and money to try this "conversion" by myself, once again, thanks a lot!!!

Yes all the gears from m2y4 fit on the D2a4 shafts, as long as you use the bearing sleeve that matches. But the hub splines don't line up perfectly.



H22 on the left:



The mainshaft itself is pretty close to the same length, but the gear stack is so much taller I actually removed the shim completely!

I think the D2L5 and D2a4 are the same dimensionally, just with different ratio's. My M2Y4 5th gear was actually slightly thinner than the D2a4 gear.

I looked at a lot of places trying to find room, but there is always another problem it will cause :hehe:

I'm lucky that we have a good supply of spare parts over here, and I work in a machine shop so it's just my time that I have to sacrifice...so much time lol

 

[SEVEN]

Once again, thanks a lot for the informations and the pictures :thumbs-up:

Ok, now i better understand were is the problem, i wish you to be able to solve all of them and make it work! :smilejap:

In my case, i have nearly finished the reassembly, maybe i'll found some time during September to try my new gearbox!

Good luck!:wave:

 

[Team Paradigm]

Totally off topic but 2 thumbs up for the AutoCAD in the background Pilon

 

[TheBense]

Curious about feasibility of running that mainshaft in later F/H trans. I like that 2nd gear.

 

[007Pilon]

Curious about feasibility of running that mainshaft in later F/H trans. I like that 2nd gear.

From my own testing and research, F22/H23 transmissions should have the same length mainshaft as the D2A4/D2L5 and H22 is slightly longer.

I have an H23 transmission that I would like to swap the internals into my D2A4 but I haven't taken it apart yet to confirm the mainshafts are compatible.