after wrestling around with my tranny for an hour i finaly decided to pay attention to detail... the input shaft on an si tranny is a little bit bigger (not sure of the exact size) than the dx input shaft and the si input shaft has 21 splines on the shaft the dx tranny has 20 splines... duhhhhh

my question is the flywheels the same for a dx an si... are they the same size same # of teeth ect.

the dx tranny has 2 groves on the end of the input shaft and the si tranny i got has no groves... isint there a way to tell what year the tranny is out of by these groves?

p.s. i have a d15b that im trying to put a si close ratio tranny in and it had the dx tranny is it

any help is much much appreciated

chris

 

88's have differnt teeth counts on the input shaft as far as I know, and I thought dx and si input shafts were the same for their respective years.

 

than i might have a tranny from an 88 (i hope i ordered the correct clutch )

 

Here is the breakdown:
A 1988 civic have no rings on the imput shaft. They also share the smaller (carry over from 1st gens) imput shaft/clutch hub. 1988s are really all by themselves. 1989, great year for the drivetrain. 1989 civics have one ring on the imput shaft and they finally upgraded to the newer style, larger imput shaft however in stock trim they stilll used the "smaller" flywheels like the 88s. 1990 and 1991 transmissions have 2 rings on the imput shaft and of course have the larger imput shaft but in these years they upgraded to the 200mm clutch disc and slightly larger flywheel to compliment this package. You can use a 92-00 civic sohc clutch disc (220mmm disc) and pressure plate on a 90+ flywheel on any civ with a 1989+ trans and 1990+ flywheel. I wonder if this is any help to you...I've done many hybrid clutch/flywheels/trans on many a civic.

~Alex

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slowcarguy &raquo;</TD></TR><TR><TD CLASS="quote">Here is the breakdown:
A 1988 civic have no rings on the imput shaft. They also share the smaller (carry over from 1st gens) imput shaft/clutch hub. 1988s are really all by themselves. 1989, great year for the drivetrain. 1989 civics have one ring on the imput shaft and they finally upgraded to the newer style, larger imput shaft however in stock trim they stilll used the "smaller" flywheels like the 88s. 1990 and 1991 transmissions have 2 rings on the imput shaft and of course have the larger imput shaft but in these years they upgraded to the 200mm clutch disc and slightly larger flywheel to compliment this package. You can use a 92-00 civic sohc clutch disc (220mmm disc) and pressure plate on a 90+ flywheel on any civ with a 1989+ trans and 1990+ flywheel. I wonder if this is any help to you...I've done many hybrid clutch/flywheels/trans on many a civic.

~Alex</TD></TR></TABLE>

thats what i was going to say

 

can anybody explain to me why the 88 clutch and transmission will not work with the90+ pressure plate and flywheel... or even the 88 flywheel... is the clutch and surface area on the flywheel different sizes???

is it more worth my effor to go out and find a 90-91 si transmission

p.s. when i measured the input shaft on the 88 with a micrometer the input shaft on the 88 was larger than the input shaft on the 90 tranny...

or even better question... can i put the input shaft and the 5th gear from the 90 dx tranny into the 88 si tranny with the reverse gear and 1st-4th, because i do alot of driving on the inerstate where if you do under 80 you get passed like you are sitting still and we all know si transmissions are not good for a long trip doing 85-90

this way i would have 1st-4th close ratio and 5th gear would be geared really high for a quiet ride on the highway

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slowcarguy &raquo;</TD></TR><TR><TD CLASS="quote">Here is the breakdown:
A 1988 civic have no rings on the imput shaft. They also share the smaller (carry over from 1st gens) imput shaft/clutch hub. 1988s are really all by themselves. 1989, great year for the drivetrain. 1989 civics have one ring on the imput shaft and they finally upgraded to the newer style, larger imput shaft however in stock trim they stilll used the "smaller" flywheels like the 88s. 1990 and 1991 transmissions have 2 rings on the imput shaft and of course have the larger imput shaft but in these years they upgraded to the 200mm clutch disc and slightly larger flywheel to compliment this package. You can use a 92-00 civic sohc clutch disc (220mm disc) and pressure plate on a 90+ flywheel on any civ with a 1989+ trans and 1990+ flywheel. I wonder if this is any help to you...I've done many hybrid clutch/flywheels/trans on many a civic.

~Alex</TD></TR></TABLE>

those are 220mm discs?? 90-91 are 212mm so how would a 220 work on the same flywheel?

 

I have a massive little diagram for this which is really helpful, but I fubared my web server. If someone wants to post it pm me or something and I'll send it to you.