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gears?

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Old Jul 4, 2010 | 07:11 AM
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stmfttr05's Avatar
stmfttr05
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Default gears?

Total noob, trying to learn.ive been reading up on gears but i dont seem to understand the purpose other than you need diffrent gears for when you get 35's or 37's. can someone explain to me what exactly the gears accomplish. do they give more power to help turn the bigger wheels or do they make them need less power to turn the bigger wheels.
 
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Old Jul 4, 2010 | 08:09 AM
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05Dakotaho
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Originally Posted by stmfttr05
Total noob, trying to learn.ive been reading up on gears but i dont seem to understand the purpose other than you need diffrent gears for when you get 35's or 37's. can someone explain to me what exactly the gears accomplish. do they give more power to help turn the bigger wheels or do they make them need less power to turn the bigger wheels.
There are 3 things that effect the "effective" final drive ratio.

1. The engine crankshaft to transmission output ratio.
2. The drive shaft to axle gear ratio.
3. The tire height to axle rotation ratio.

When you change any one of the three; you "effectively" change the "final drive ratio".

When you increase tire height it is the equivalent of shifting the transmission to a higher gear or changing the differential gear to a higher ratio in terms of torque and/or acceleration performance.

Changing the differential gear to a lower ratio is the preferred method (in terms of expense and parts availability) to compensate for tire height changes if you want to maintain the original "final drive ratio" but it is not necessary.

The net effect of your taller tires will be reduced torque/acceleration in each respective transmission gear and potentially better gas mileage at highway cruising speeds.
 

Last edited by 05Dakotaho; Jul 4, 2010 at 02:08 PM.
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Old Jul 4, 2010 | 05:07 PM
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stmfttr05
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Originally Posted by 05Dakotaho
There are 3 things that effect the "effective" final drive ratio.

1. The engine crankshaft to transmission output ratio.
2. The drive shaft to axle gear ratio.
3. The tire height to axle rotation ratio.

When you change any one of the three; you "effectively" change the "final drive ratio".

When you increase tire height it is the equivalent of shifting the transmission to a higher gear or changing the differential gear to a higher ratio in terms of torque and/or acceleration performance.

Changing the differential gear to a lower ratio is the preferred method (in terms of expense and parts availability) to compensate for tire height changes if you want to maintain the original "final drive ratio" but it is not necessary.

The net effect of your taller tires will be reduced torque/acceleration in each respective transmission gear and potentially better gas mileage at highway cruising speeds.
ok ty. i think i get it now.
 
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