street_ride14

Never really looked at my transmission code until today, I always thought that it was the factory M2F4 USDM 4th Gen VTEC tranny. Well today I look at the code and it reads M2A4 ( JDM VTEC, non-LSD ). I bought the car this way. VIN number of vehicle states that this is a true 4th-Gen VTEC, USDM. Engine block is stamped H22a1.

Anyways my question is ... what are some of the advantages or maybe disadvantages of having this tranny as opposed to the M2F4 that I thought I had. I'm just starting to learn about gear ratios, but from what I have gathered through research thus far are the following specs ...

M2F4 - 3.307 - 1.950 - 1.360 - 1.071 - 0.870 - Final 4.266
M2A4 - 3.307 - 1.950 - 1.360 - 1.071 - 0.787 - Final 4.266

5th gear is longer in the M2A4, so less RPM on highway when cruising ?

Speedra500

yes

A Blue Lude

4th gear on the M2A4 doesn't seem right to me.

lude98SH

M2F4
1 -3.307
2 -1.950
3 - 1.360
4 - 1.071
5 - 0.870
FD 4.266

M2A4 (JDM)

1. 3.307
2. 1.950
3. 1.160
4. 1.034
5. 0.787
FD 4.266

street_ride14

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lude98SH &raquo;</TD></TR><TR><TD CLASS="quote">

M2A4 (JDM)

1. 3.307
2. 1.950
3. 1.160
4. 1.034
5. 0.787
FD 4.266

</TD></TR></TABLE>

What is your source for this information ?

lude98SH

faqs

street_ride14

I don't think that information is accurate. Look at the M2B4 ratios ( JDM - LSD ). Why are they different from the M2A4 ( JDM - NonLSD ) ? These are supposed to have the same gear ratios, the only diffrence should be that one comes with LSD and the other does not. As I understand, those ratios were calculated from gear tooth counts and not referenced with the Japanese Helms.

Here is the link for reference .. https://honda-tech.com/zerothread?id=549372

Does anyone know the gear ratios for the M2A4 transmission ?? (( From the Helms would be most helpful. ))

lude98SH

well if ur that sure of this then make sure to mention it to the moderator i guess, to change the info or look into it more

lude98SH

now that u mention it i remember seeing descrepencies in the information for the m2a4 i think. I remember i posted something about the info but i dont think anything was done, i could be wrong it was awhile back.

H22EG'z

i jus put some money down on a h22a1 with a M2A4 Tranny, but on the paper it says LSD in red.. is this a typo? or did someone install it? i havent bought it completely so i cant take it apart, but i paid for the LSD.

NirVTEC

The important part is I got 29mpg(with S2S1 cams i/h/e tuned with a VAFC2) going 80mph on a Fill to Drain cruise with this trans....../done

92civlude

You dont have to take it apart. Look in the axle hole. If there is a space between the spider gears, Its an open diff. If there is any sort of steel sleeve or block, Its a good bet you have LSD.

allentownrep

i think you have it backwards...if you look thru the axle hole and theres a bar its non lsd. and if you can see all the way thru then it is an lsd

gaydm.accord

both m2f4 and m2a4 = non lsd


it is a possibility lsd was put in afterwards. the bar = non lsd, if you can see all the way through its lsd. what ^^^ said

92civlude

If its equipped with a phantom grip or similar, it will have a cross-pin. He said it was an M2A4 with LSD.(which Honda never made) It could have a phantom grip or similar. Yes, without the crosspin, it could be a helical LSD Aftermarket or Honda. But, between the gears, if its a phantom grip or Honda, you will see a steel "block". No space. MY POST SAYS A SPACE BETWEEN THE SPIDERS FOR OPEN DIFF. Thanks for the input!

92civlude

H22EG'z

aight, ill have to go check it out today, see if i can see anything, thx guys

H22EG'z

aight so i went and checked it out, the M2A4 Tranny on the H22 im buying does NOT have the bar through the tranny and the mechanic said he also inquired to a Honda "Master Mechanic" about it ... I guess, anywho he showed me another M2A4 that had the bar through it. So i just told him "well im guessing it has an aftermarket LSD" and got it in writing that id get one from them if it for some reason turned out otherwise

integra_101

I have a 93 JDM H22a with a m2a4. I bought a m2f4. I know it will swap right in. But what about the VSS.

Also is there anything else that I would have to swap/worry about.

Thanks

Z-EP3-02

This is correct.
Bar=Non LSD
Teeth hollow hole=LSD