difference between a1 and s1 and ys1 tranny
 

Just wondering if anyone can enlighten me on what the differences between the a1, s1, and ys1 tranny are? I was searching for some tranny guide that tells me what the differences might be but couldn't find one. I know the a1 is from the 90-91 integra but thats about as much as I know.

I've heard lots of people using s1 and ys1 that has factory lsd, but what about the a1? Are there any disadvantages in using the a1? I'm thinking that there are no differences but just need a confirmation on this.

This tranny is going in a project car and not daily driving if anyone cared to know.

Thanks in advance

Re: difference between a1 and s1 and ys1 tranny (B16Drag)
 

If I remember correctly, both the A1 and S1 were 90-91 Integra units (one is rarer than the other...). The YS1 is the 92-93 Integra gearbox - both LS and GSR gearsets came in these.

The YS1 is a better unit in my opinion. It is internally (nearly) indentical to the 94+ hydraulic clutch transmissions, which means it is somewhat stronger and will accept newer gearsets (I run a 97 GSR gearset and ITR LSD in mine).

The clutch disc you use will be dependent on which transmission you have (90-91 vs. 92+). Other than that, you can use any of them interchangeably.

Factory LSDs are found in JDM units only (if at all - don't know about the A/S1), and are pretty rare as far as I know (especially in the YS1).

Re: difference between a1 and s1 and ys1 tranny (acy76)
 

Where do you look to see what kind of tranny you have? I'm assuming that it is stamped somewhere on it, but where?

Re: difference between a1 and s1 and ys1 tranny (sdgenxr)
 

there is no stamp there is a sticker that might have come off if u r looking at the tranny bolted to the motor it is right next to the block code https://honda-tech.com/forums/images...es/emsmile.gif