92eghb

I have a 98 base prelude with the m2y4 transmission in it. The gas millage is killing me and I have decided to swap the 5th gear out with the 5th gear from the accord p2xx transmission. From my research the m2y4 has a final drive of 4.266 and and 5th of 0.812. The p2xx transmissions have a 5th gear of 0.685. I know the part are interchangeable but my question is how will it affect the drivablity of the car. With the stock m2y4 at 3500rpm with 205/50r16 I'm driving at 72mph. If I swap the 5th gear at 3500rpm I'd be traveling at 86mph or 70mph at 2850rpm. Any input would be apreacited.

h22a_black

i dont believe the parts are directly interchangable, the accord gear will need some machining

David @ Synchrotech

iTrader: (1)

You are 100% correct. The Accord 5th gears will work but the countershaft 5th gear must be machined down to the same height as the H22 gear.

92eghb

I knew some work was going to be needed. My question is still unanswered Though. How will the drivability of the car be affected going from stock short m2y4 gears to the long fifth gear of the accords?

David @ Synchrotech

iTrader: (1)

The customers that I have done this for love it. You will have more RPM drop going into 5th but the transition is still smooth and the lower RPMs on the freeway make for a more comfortable ride and better gas mileage.

92eghb

What do you charge to do this if I bring the gears and transmission

extralargenog

iTrader: (1)

accord 5th is retarded long and rediculous IMO, and thats all t is is an opoinion. Put a H23 fifth in it. Youll need to machine it down as well. I have a cuple H 5th sets LMK if you want one ;O)

92eghb

From all the research I have done everything say the h22 and h23 have the same fifth gear and final drive as far as ratio. A longer gear is what I want. I commute 80+ miles for work everyday and the gas cost are killing me.

extralargenog

iTrader: (1)

h23 5th dude... why wouild you neuter the trans with a f fifth?

92eghb

Okay I found a more comprehensive chart with all the accord and prelude trannys http://www.************.com/forums/s...d.php?t=312544( sorry mods of this link is not allowed)
As to you commit about neutering the trans. I'm not building a drag car and I don't street race... Even if I did how often does a street race see fifth gear. The only reason I want to do this mod is fuel economy. I realize I could just swap in the accord trans and call it a day but i want to maintain the sport feel of the prelude around town but once on the highway I want better gas milage.

David @ Synchrotech

iTrader: (1)

Sent you a PM price

extralargenog

iTrader: (1)

Ya Definately dont swap the accord trans, IF you insist on the Really high 5th, just swap the 5th for an overdrive of sorts LOL...


The accord trans in an H is rediculous and no fun, at all.


Dave is THE MAN. He'll set you up properly for sure.

preludeblaiz

Hello I want to do that modification too on my M2Y4. Can you tell me what is the complete number of accord tranny (P2...)? And if you have done the modification, can you tell me what kind of machining I will have to do on the gear. Thanks

92eghb

It doesn't matter any p2xx trans will work. I don't know what machining needs to be done. Hit up synchrotech they'll take care of all of it for a fair price.

David @ Synchrotech

iTrader: (1)

We use the P2A8 gears from a 1998 Accord 0.685 ratio and have a local Machine shop surface grind both sides of the c/s gear to match the M2Y4 gear. The machining is $60 if you have a good set of P2A8 gears or $195 for the set if we provide the gears.

preludeblaiz

Thanks.
can you tell me how thick you remove the gear. I want to machining before I remove my tranny and I dont know what is the thikness of an M2Y4 5th gear. I'm from québec city so I will do the job myself.

preludeblaiz

Thanks.
can you tell me how thick you remove to the gear. I want to machining before I remove my tranny and I dont know what is the thikness of an M2Y4 5th gear. I'm from québec city so I will do the job myself. Or do you ship in Québec?

preludeblaiz

Thanks.
can you tell me how thick you remove the gear. I want to machining before I remove my tranny and I dont know what is the thikness of an M2Y4 5th gear. I'm from québec city so I will do the job myself. If you have photo of an older job can you post it too.
Thanks

David @ Synchrotech

iTrader: (1)

Sorry but I'm not willing to post the machining process. We ship worldwide if you want to order the gear set. If you want to do it yourself, I suggest taking the gears out of your trans and machining the Accord gears to match.

preludeblaiz

Ok and how I proceed to order the gear set. I go on your internet site and I don't find it. Let me know and I will order one set. thanks.

David @ Synchrotech

iTrader: (1)

PM sent

f20b jones

I have the accord fifth in a m2b4 tranny. It doesnt hinder the tranny as at all and helps a tone with gas mileage. Deffently a great upgrade let syncrotech do it you want regret it . I get 35 mpg with a built h series that makes 252hp and runs 12.2 in the quarter .

CanadianLude

hey guys i just bought a 1999 prelude sh for my gf and i wanna do the 5th gear change anywhere i can get it done in Alberta if i get the gears from synchrotech ? thanks any input is appreciated

k1500rob

Can you please explain what you guys mean by "height" of the gear? Is it the actual thickness that we are concerned about? or is it the diameter?

Thanks Guys

David @ Synchrotech

iTrader: (1)

You will need to measure the H22 gear and surface grind the raised area on top and bottom of the Accord countershaft gear until it matches the H22 gear. It is not the gear diameter you are changing, it is how tall the gear sits on the shaft.