I was wondering if my 99 si tranny diff. broke can I use a LS diff. Just remove the broken one and replace it without changing the ring gear (is it the same?). Are the LS syncros/gears? interchangable with the Si's? what would I have to do to switch the syncros/gears?

 

If you're referring to LS transmissions 92+, then:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civic2slo &raquo;</TD></TR><TR><TD CLASS="quote">I was wondering if my 99 si tranny diff. broke can I use a LS diff. ?</TD></TR></TABLE>

Yep, same part.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civic2slo &raquo;</TD></TR><TR><TD CLASS="quote"> Just remove the broken one and replace it without changing the ring gear (is it the same?).</TD></TR></TABLE>

No, you will have to use the Si ring gear.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civic2slo &raquo;</TD></TR><TR><TD CLASS="quote">Are the LS syncros/gears? interchangable with the Si's? what would I have to do to switch the syncros/gears?</TD></TR></TABLE>

You would have to compare part numbers. You could start by checking ratios -- if they're the same for a given gear, chances are decent that they will be the same part. You might find that 1st gear is the same, but I would guess that none of the others are.

The synchros for all gears 1,3,4,5 and R will most likely be the same. 2nd gear synchro in the VTEC transmissions is dual-cone, and thus not the same as the LS.

You could also swap the internals over completely if you wanted to.

http://www.acuraparts247.com and http://www.slhonda.com are great sites for checking part numbers. Honda and Acura numbers will interchange -- check the Si diff against an LS diff.

 

thanks for all the info.