What are the measurements of the input shaft

So I’ve searched all over and can’t seem to find a lot of information other than 'it’s been covered already". Any of the threads linked are dead. I suppose g2 is getting old, most of the useful threads have lost their pictures.

My questions are…
What are the measurements of the input shaft on the a1 and ys1 for identifying them?
What LSD can be used in an a1?

Thanks in advance

I really need an answer to this, and I can’t figure out anywhere to get the info. I need to order a rebuild kit and my input shaft doesn’t look like the “fat splines”. It is marked as an a1 though on the housing

The “splines” have nothing to do with it. Both 1st gen (89-91) and 2nd gen (92+) B series transmissions have the same number of splines on the input shaft, the only difference is the shaft diameter.

89-91 = 24 splines / 25mm diameter
92+ = 24 splines / 26mm diameter

You can confirm this info at www.exedyusa.com Just look up the clutch kit for both a 90-91 Integra and a 92-93 Integra, the specs are then listed for each clutch kit.

If your trans says A1, then it’s a small diameter trans and needs the 90-91 Integra clutch kit.

92-93 GS-R

90-91 J1/A1

in other words…even for “92-93” LS trans…the 90-91 will fit…search competition clutch website…the 92-93 specificially say from the motor type the B17A

Thank you very much, gentleman. I had heard the a1 had “fatter” looking splines… Anyways, it measures 24.8mm.

I wanted to be completely sure the internals hadn’t been swapped, if that’s even possible. My car has been a bit confusing. Nothing seems to match what I find on the internet. Lol

[QUOTE=integra_hot;2292482]
in other words…even for “92-93” LS trans…the 90-91 will fit…search competition clutch website…the 92-93 specificially say from the motor type the B17A[/QUOTE]
Assuming I’m not mis-reading what you typed, this info is incorrect. ALL 92+ b series transmissions have the larger shaft diameter. Doesn’t matter what car, what engine…etc So, a 90-91 clutch disk WILL NOT fit a 92-93 LS transmission (Pressure plates are interchangeable). ALL 92-93 integras use the same clutch kit regardless of trim level.

386: your a1 is a SMALL shaft trans. The ONLY large shaft b series cable trans is the YS1 (there are 3 versions of transmissions with this demarcation). Internals ARE NOT interchangeable between 89-91 and 92+ b series transmissions (some small parts might be, but the main parts are not - for instance, you cannot put the main shaft from a 92 Trans into a 91 case). The only way your A1 would be large shaft is if it was actually a YS1 that someone had glued an A1 decal onto.

You can also tell the 1st gen vs 2nd gen from the case itself. I forget the exact differences though.

So I’m assuming the differential bearings are different as well?
I appreciate you taking the time to reply, Colin.

www.acuraautomotiveparts.org is a great resource to check if parts are the same.

[QUOTE=Colin;2292490]Assuming I’m not mis-reading what you typed, this info is incorrect. ALL 92+ b series transmissions have the larger shaft diameter. Doesn’t matter what car, what engine…etc So, a 90-91 clutch disk WILL NOT fit a 92-93 LS transmission (Pressure plates are interchangeable). ALL 92-93 integras use the same clutch kit regardless of trim level.

386: your a1 is a SMALL shaft trans. The ONLY large shaft b series cable trans is the YS1 (there are 3 versions of transmissions with this demarcation). Internals ARE NOT interchangeable between 89-91 and 92+ b series transmissions (some small parts might be, but the main parts are not - for instance, you cannot put the main shaft from a 92 Trans into a 91 case). The only way your A1 would be large shaft is if it was actually a YS1 that someone had glued an A1 decal onto.

You can also tell the 1st gen vs 2nd gen from the case itself. I forget the exact differences though.[/QUOTE]

oh wow, informative for me