1KR-FE Gearbox swap

They say silly questions don’t exist…

But I had an idea. I’m not too happy with my Cuore’s gearbox, why? Because the gears are just too long for what I’m using it for. Spirited driving is hampered by the long gears and after fitting 14 inch wheels the situation got even worse. It feels like the gearbox pulls the engine out of its power range in anything beyond 2nd. But then I had an idea.

After driving a yaris with a 1sz-fe and my own yaris with the 2sz-fe, I noticed both cars had very short gearing. The result: faster revs, more fun, and more responsive driving at the cost of the engine screaming its way down the highway. Something I’m totally fine with since I barely drive on highways.

My question: would the gearbox from a 2sz-fe or 1sz-fe be a direct bolt on? Are the gears on the 1sz-fe tranny even shorter? I’d love to hear it!

By the looks of it, Yaris gearboxes are different in a lot of ways (casing, cable shifter vs rod shifter, hydraulicly operated clutch). Here is an example of an L276 box vs Yaris P9 gearbox

I thought maybe the 1KRFE Yaris would’ve had shorter gearing than an Aygo (which internally should be identical to an L276), but in terms of part numbers, even those two don’t match. The Yaris gearbox does fit both 1KR and 2SZ, but that doesn’t help much.

However , then I remembered that it might not even be necessary to look outside the Daihatsu brand, because the Sirion 2 came with a 1KR as well, and waddayaknow

Cuore L276

Sirion 2

With a shorter final drive, you should be able to achieve the goal of ‘shorter gears’. However, 5th gear is also shorter. This comparison is basically the same between a Sirion M1 EJ and a Cuore L7 EJVE, and I’m not a big fan of the shorter 5th gear. It is however the best option considering it’s (I think) a direct swap because of engine mounts and controls, but you can always look into mixing 'n matching the internals (although that may require some special tools and knowledge, so be careful). I’m planning on doing the opposite for my car btw haha :slight_smile:

Hope this helps! De groenten en tot sinas


Your knowledge never fails to impress! Last time I believe anything on a malasiyan forum. This should help my gearing issues quite a bit! I’d rather not mess with the gears themselves, but swapping in a different is a realistic idea. Thanks strijder :slight_smile:

1 Like

Like I said before, the gearing is also quite short up top, so do take that into consideration. Compared to stock it should be like this:

(4,50,75) /(3,940,71) = 1,206

So, 20% more revs in 5th gear


I will keep that in mind! I’m totally fine with that though, this car barely gets any highway time. The comfort of shorter gears on my daily commute outweighs the noise and extra fuel consumption :slight_smile:

1 Like