Hello all,

I have a 95 Civic VX, and also a spare VX transmission.

A friend of mine has a 92-95 Si D-series transmission that I can have for free, but it needs bearings.

Is it possible to swap the VX 5th gear into the Si trans while I'm in there?

I haven't been on the site in a long time - any help (including links) is greatly appreciated.

 

The 92-95 Civic VX and SI both use the same 5th gears.

OEM numbers 23581-P20-C00 and 23461-P20-C00

 

Thank you.

I'm confused though - does that mean they are the same ratios?

I also found this thread here:
http://marketplace.honda-tech.com/sh....php?t=2954339
(relevant posts #16 & #18)
which makes it look like they are different.

I'm not questioning anybody, just trying to wrap my head around this...

 

Yes, well sorta. The '92 - '95 Civic Si hatchback and Del Sol Si transmissions have a slightly lower 5th. If the trans came from an EX coupe or sedan it will have identical gearing other than 5th gear is slightly taller (same as all other '92 - '00 5th gears) The reason 5th gear on a VX seems so much longer is due to the final drive.

 

The 5th gears on the Civic Si and Civic VX are the same exact gears. The DelSol Si has different 5th gears but only slightly.

 

Thanks guys. I really appreciate the help!

I guess I was trying to ask if I could have the same highway revs in 5th that I have now in the original VX trans, but if I am reading things correctly that isn't possible.

Would it be beneficial at all to use the Si gear sets inside the VX case, while retaining the original VX final drive (diff)?
I really just want a little better acceleration, while keeping the same cruising rpm on the highway if possible...

 

That is correct, it isn't possible to run an Si final drive and keep a low cursing RPM.

Bare in mind that the VX trans uses the same 1st, and 5th gears the Si uses. It will help you somewhat, but it wont be a night and day difference like an actual Si trans.

What engine is it? If it's a VX it's kind of important to keep the cruising RPM low to keep the engine in vtec-e and leanburn mode.

 

Thank you again, and yes you're right about the highway cruising RPM.

It is an actual VX, totally stock.
The issue for me is that I was running 185/60/13 tires (shorter than the factory 175/70/13), but now I am running 185/60/14.

Besides being slightly taller, the 14s are heavier. The car is now very, very slow to accelerate - even more so with the A/C on. I'm older, so I don't care about speed, but my gas mileage has also gone down somewhat as well (around 40 vs. 48).

I was thinking that if the mpg is slightly lower than what I'm used to getting, then a few mpg less might be a fair trade for getting decent acceleration back.
Of course, a z6 swap would be great, but I just don't have the money right now, and I'm sure the gas mileage then would possibly only be around 30 or 32 mpg.

 

Thank you again for all your help.

After reading over everything in this thread, I've decided what I'd like to do is to use the Si gear sets inside the VX case, while retaining the original VX final drive (diff).

Can I just swap the Si shafts & gears over to the VX transmission case?

 

You need to swap the gearset and the mainshaft from the Si into the VX case, you will need to retain the countershaft from the VX. Also, you will need to shim the mainshaft.