Allion 2008 A18 Gearbox Trouble – Repair or Replace?

arunwij · Sunday at 12:12 PM

Hi everyone 👋

I’m looking for some advice regarding a gearbox issue in my Toyota Allion 260 (2008, A18 – ZRT260).

Vehicle History:

I bought the car in 2023. A few months in, I noticed an unusual noise from the gearbox. The car drives normally when first started, but after a few kilometers, the noise appears—especially under higher RPMs and when going uphill.There were no initial pulling power issues, but I did notice occasional jerkiness when accelerating at lower speeds. I got it checked in Pannipitiya, and the technician said the gearbox had been previously repaired. We repaired the gearbox and changed the oil. The noise stopped for a few months but eventually returned. I decided to use the car with noice anyways.

I continued using the car without major issues until recently. Now, there’s a serious problem, sudden loss of pulling power. The car won’t go above 40 -50 km/h even with full throttle, and RPM just climbs. It also struggles badly on hills. If I let the car cool and restart, it works for a short while before the issue returns.

My Questions:

1. Can anyone recommend a reliable place to properly check and diagnose this issue?

2. Since I’ve already repaired the gearbox twice, is it worth trying to repair it again?

3. If I go for a gearbox replacement, are parts available for the A18 model? Can I use a gearbox from the A15 model instead?

Thanks in advance for your support and advice! 🙏

iRage · Monday at 02:37 AM

On 3/23/2025 at 12:12 PM, arunwij said:

1. Can anyone recommend a reliable place to properly check and diagnose this issue?

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Sorry I don't live in SL so I don't know any reputable place.

On 3/23/2025 at 12:12 PM, arunwij said:

2. Since I’ve already repaired the gearbox twice, is it worth trying to repair it again?

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It probably would be reasonable to replace it. However, also keep in mind that you would not know what the history of the new-to-you transmission is (as it is from a scrapped car in Japan). So that too might develop problems after a short period. The newer the CVT it is the better as the problems with the older variants were addressed and technical updates were made to the newer variants of the gearbox. Toyota Japan does have new gearboxes but that costs about 300,000yen just to buy. So when you add in shipping cost, taxes, dealer margins you probably will be looking closer to 1.5mil LKR. Depending on how long you keep the car for, how much you bought it at and looking at the price of new cars...you may want to consider this option if you can afford it.

On 3/23/2025 at 12:12 PM, arunwij said:

3. If I go for a gearbox replacement, are parts available for the A18 model? Can I use a gearbox from the A15 model instead?

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Technically yes. The entire series came with a K31x series transmission. So the CVT from a 1.5 will fit a 1.8. HOWEVER, here is where things go a bit south for you. The 1.5 has the K310 CVT while the 1.8 has the K311 (or K311F for anything after 2010) CVT. They look the same...and more or less the same except for the final drive. The final drive ratios between the two are different. The K310 has a higher ratio (shorter gear) so torque delivery will be slightly different and engine will rev a bit higher at high speed than your current gear box). The K311 has a lower ratio (longer gear), so torque delivery will be a bit more relaxed, and the engine will sit at slightly lower RPMs at high speed than the K310.

You should try to get the K311 as much as possible.

arunwij · Monday at 04:07 AM

Thank you so much for your detailed response 🙏

I’m planning to keep the car until around 2027. I’ll look for a replacement K311 gearbox, but going for a brand-new one at around 1.5M is a bit out of my budget.

Worst case, if I go with a K310 instead, will it negatively affect the engine or fuel efficiency? Right now, I’m getting around 12 km/l outstation and 10 km/l in the city. From what I’ve heard, the K310 might actually make it feel a bit sportier 😂

iRage · Monday at 05:24 PM

On 3/24/2025 at 4:07 AM, arunwij said:

will it negatively affect the engine

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Like will it break and have issues ? No..highly unlikely.

On 3/24/2025 at 4:07 AM, arunwij said:

fuel efficiency?

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Hard to say..,.probably will especially at highway speeds. However, also remember that being a CVT the ECU will try to adjust the CVT to optimize engine performance (in this case economy)

On 3/24/2025 at 4:07 AM, arunwij said:

From what I’ve heard, the K310 might actually make it feel a bit sportier 😂

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Feel..yes..actually...questionable. The final drive ratio is higher in the K310 so that it can move a low torque engine. The K311 final drive ratio is lower so that is can move a higher torque engine fuel efficiently and maintain doing so at a higher speed. Now, you are taking a transmission mapped to move a low torque engine and mating it with a higher-torque engine. So now the engine needs to rev up more than before and with the higher torque, that will come faster. This also means that the engine reaches its limits a bit sooner than before so it won't be as fast as before.