cx/vx type final drive swap for 93 honda civic 5 speed lx 4 door? From 4.06 to 3.25?

[marcb]

Hi,

I'm brand new here and new to having a honda. I recently bought a '93 Civic LX 5 speed with 103k to avoid using my '04 Silverado for errands and running around. The civic gets 38-41 mpg so far vs my Silverado averaging about 16-17 in the cold months. I'm wondering if it's possible (practical) to change the final drive on my civic lx from 4.06 to the 3.25 that came in the CV and VX? Can anyone comment on what it would likely cost for parts and what would be involved from a labor standpoint to accomplish it.

I plan to keep the car for many years. I usually carry a light load such as just me or a school run picking up the kids.

Great site btw.

Thanks to all.
marcb

[cems70]

You're better off buying a used CX or VX transmission from a boneyard and swapping it in. Should be able to find one for $150 or less. The parts alone to change out the final drive on your current tranny will cost you more than $150. I and other members have done the VX tranny swap....I did mine for my '95 Civic DX hatchback. I saw about a 6 - 8 mpg improvement in FE. Having previously owned a '95 VX, I have to admit that the VX engine was much better suited for the tall 1 - 5 gears in the VX tranny. The DX's power curve is just not as suited for it...it's much more difficult to drive in stop and go traffic, and it has no gitty-up, but the improved FE is still worth it.

[marcb]

I made a few calls to local tranny shops and found prices of $350 to $500 for labor to install a tranny I bring to them for a Honda Civic. The say it's about a 6 hour job. Keep in mind the $350 to $500 is JUST for the labor and doesn't include the tranny, oil, shipping, etc...

A couple of shops also mentioned the clutch should be swapped since the tranny is out. (Car has 105K). I'm new to Honda Civics. What's the life range of a Civic clutch? What do you think?

One shop said I should be very careful to make sure that the AXLES match if swapping trannies from different model cars. They suggested BOTH axles be replaced at swap in. In my case I'd be swapping an LX tranny for a VX or CX tranny going from a final drive of 4.06 (LX) to 3.25 (CX/VX). Are there AXLE differences from a '93 LX to CX/VX? I didn't thnk so and when I called parts stores about axle prices they NEVER ask wether I have an LX or CX or VX so I'm thinking there is no difference in axles between the LX and the CX or VX. Make sense?

Total estimated cost might be $700 or so to do based on a $400 install + $300 tranny including freight/shipping. If I estimate I'd gain about 7 MPG I'm not sure it would make economic sense.

I change my oil and basic stuff but I don't think I could tackle a tranny swap plus I have no real lift if the car needs to be lifted. I have a floor jack. Have you ever swapped a Civic tranny?

My Civc has been averaging 39-40 MPG. With a tranny swap I'd guess I could add about 7 MPG. At an estimated $700 cost it doesn't seem to make economic sense. What do YOU think about it?

Thanks!
marcb

[GasSavers_Erik]

I did a tranny swap on my 87 Civic last year. You can swap the tranny with 1 jack and 2 jackstands and a few wooden blocks to put under the oil pan.

[Danronian]

I don't think it will pay for itself, unless you do the tranny swap yourself. TO change the final drive, the tranny must come out, so either the swap or the final drive swap will be about the same for labor/cost.

Honda clutches can last over 200k, but it all depends on the previous owner. TO be safe, I would replace it while the tranny is off.

The comment about the axles the one shop made is 100% incorrect. The axles for all 92-95 civics are the same, no matter if it's an ex/cx/dx/vx tranny.

Next time post a thread like this in the general tech section on here, and you'll get a lot more responses.

Good luck

[StorminMatt]

Here's something else to consider. If you have to pay someone else to do everything, then the cost of changing the final drive is going to be even HIGHER. Not only would the parts probably have to be purchased new, but you would also have to pay someone to open the transmission.

Here's how I look at the whole thing. If you have to pay someone to do the job AND pay top dollar for a transmission, it's probably not worth it. If you REALLY want to do this, the only really cost-effective way to do it is to get the transmission locally from a private party or self-service wrecking yard AND swap the transmission yourself.

[marcb]

What's involved in removing a tranny in a Civic of this vintage? This seems too difficult to me. I have no compressor or impact tools or local assistance. Just basic hand tools and a garage. I'd love to bring down the RPM's and squeeze out another 7 MPG. With 2 kids in elementary and 1 in middle school and scout meetings, baseball, visiting my Dad and hr away seems like I'm racking up *lots* of miles. Thanks!

[GasSavers_Erik]

No impact tools should be needed.

You can "checkout" a loaner ball joint separator at many auto parts stores (you'll have to separate the ball joints to swing the spindles outward and pull the axle shafts out of the transmission).

Mine was an 87 Civic- so your civic might be a tad different.

[StorminMatt]

You might want to reconsider that transmission swap. First of all, it is a myth that taller gearing ALWAYS helps fuel economy. For instance, my 1989 Civic DX HB seems to REALLY hate the HF transmission that I slapped on it. Freeway mileage did not increase by one bit. But I lost TONS of drivability. I should also note that city MPG will probably DECREASE quite significantly with a VX/CX transmission since your gear choices will go down, and you might find yourself digging deeper into the throttle just to keep up with traffic. So as long as ou stick with your stock D15B7, the stock transmission is probably best. ESPECIALLY since it sounds like you run ALOT of errands around town. I would not go with a CX/VX transmission unless you get an engine (ie D15Z1) that was designed to run efficiently at low revs. And even then, it might not be the best choice for city driving.

[marcb]

Thanks. All things considered I'm going to keep it simple and use good driving habits and other tips covered here but put changing the final drive and tranny swap for somewhere down the road if at all. If I can get around 40 average that'll be good for me. Thanks alot for the responses! marcb