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I'm not sure to understand exactly what you want to do. :unsure: What do you means by ''bigger wheel'' and ''small shafts''... can you explain it with different words please?
I think he means changing the final drive gearing; the bigger wheel being a bigger driven gear. Where you'd even get that I have no clue unless you could use a whole transaxle from a different year RAV4 but then you'd also have to change the rear differential.

Way back when we had that option with the underpowered 70HP Tercel 4WD wagon since Toyota changed ratios midway thru the production run.

IMO, altho the intention is on track the implementation is FAR more complicated than the idea.
The practical solution: Buy the Suzuki!
 

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The RAV would be elevated to another class of awesome if it just had a two speed transfer case. I've read Toyota was incorporating this into the FT-4X concept.
 

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The RAV would be elevated to another class of awesome if it just had a two speed transfer case. I've read Toyota was incorporating this into the FT-4X concept.
The 4WD Tercel wagon didn't have a two-speed transfer case but did have a sixth gear the FWD sedans didn't - that being "EL", an extra low first gear which was great for off road ALA you didn't need to go more than crawling speed.
 

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And there lies the problem right? Like the problem the OP states, the absence of a low speed transfer case, tall 1st gear and larger tires. I call that 3x strikes and you're out.

The math on going to larger tires is easy enough to pencil out, but we haven't even begun to factor in the weight penalty of larger, off road tires. A general rule is 3:1, be it that rotating mass generates 3x the force then does static weight. Provided the OE tires weighed 25-28 lbs, and a 235/70-16C BFG KO2 weighs 37 lbs, the weight alone is doubling the tire load on the engine. In effect it's the equivalent of the engine and transmission turning EIGHT axles, not four.

This is why I run 4.88s on my Tundra for 34" tires when 4.56s would numerically cover the ratio of larger tires. You have to make up the difference lost to rotating mass by mechanically lowering the gear ratio.

. . . or adding more power. But bolt-ons only do so much.
 

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Bartlomiej; I did something today to help you understand how the RAV4.2 AWD system works. It is a very complex system that a minority of people really understand.

Our RAV4 are equipped with 3 differentials.

1- The front differential is ''open''
2- There is a center differential (viscous LSD)
3- Rear differential: most are ''open'', but there was a torsen LSD option

The front and center diffs are miniature, and they are packed side by side into what looks like a regular FWD diff. They are both open, BUT there is a viscous LSD unit inside the t-case that limits slip between the front and rear differentials... there is no locking mechanism that cancels the center diff. (Only the RAV4.1 manual transmission is equipped with this mechanism.)

Here is some photos with added info for better understanding:








So there is absolutely no place where you could install a two speed mechanism like a regular 4X4 transfer-case.
 

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Discussion Starter #26 (Edited)
Bartlomiej; I did something today to help you understand how the RAV4.2 AWD system works. It is a very complex system that a minority of people really understand.

Our RAV4 are equipped with 3 differentials.

1- The front differential is ''open''
2- There is a center differential (viscous LSD)
3- Rear differential: most are ''open'', but there was a torsen LSD option

The front and center diffs are miniature, and they are packed side by side into what looks like a regular FWD diff. They are both open, BUT there is a viscous LSD unit inside the t-case that limits slip between the front and rear differentials... there is no locking mechanism that cancels the center diff. (Only the RAV4.1 manual transmission is equipped with this mechanism.)

Here is some photos with added info for better understanding:







So there is absolutely no place where you could install a two speed mechanism like a regular 4X4 transfer-case.
Oh my this is far more complicated than I thought... ;(

Thank you for explanation it helped to understand but also showed how hard it is to modify this car.

Initially i thought to modify this wheel in transfer case:
151200



or modify this wheel:
151201


Maybe changing one of this gears would change the final gear ratio? With automatic transmision which is electronicaly controller I cannot change gears inside transmision. Only chance is to change gear ratio after the transmision.
 

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To change the final drive ratio, you would also need to change the gear on the counter-shaft.

You can't change the gear ratio in the t-case. It's geared to gives a 1:1 ratio with the rear diff, with any final drive ratio inside the transmission.
 

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Discussion Starter #28
So there is no way to change gearing in that car ;(

I would propably go with smaller wheels like 215/75 r16 next time, such wheels are much easier to spin by the engine. Especialy my rav4 is 3 door and it is quite light and dont need wide wheels.
 
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