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Old 01-22-2009, 11:50 PM   #6 (permalink)
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2nd gear in an manual transmission s10 is usually around 2:1 (it varies somewhat depending on year and model of transmission). Most EVs tend to use 2nd gear all the time. So if you go with direct drive then you will essentially be in 4th gear which is usually 1:1. To deal with this you'll need to swap to a rear end gear ratio that is about double what stock is. stock is anywhere from 3.08 to 4.11 so you'll need to find aftermarket gears in the 6:1 to 8:1 range which is a major problem.
The pinion ends up with way less teeth which equals less gear contact which means it will break much easier. I see this all the time with offroad rigs swapping in 5.29 5.87 or higher numerical gear sets. They simply are weaker than the lower numerical sets due to the ever shrinking size of the pinion gear (torque multiplication is murder on the axle shafts too). Now think about how much instant torque an electric motor puts out compared to an ICE...SNAP! Axles and pinions likely won't last long if you couple the changed gear ratios in the rear with a direct drive electric motor.

One other thing about the ratios...friend of mine has had many dodge diesels. The ones with 3.29 (or was it 3.23 or 3.08?) gears had higher GVWRs than the exact same model of truck with 4:10s. This is due to the strength issue. Also, this same friend was complaining about breaking his 4:10 dana 70 rear end under normal hauling usage. He swapped in the lower (numerically) gears to try to avoid breakage again.

An option for you is to run very small and short tires which will look better if you lower the truck anyways and run the highest (numerical) gear set that came from the factory (likely 4:10s). The combo of these two things might get you where you need to be gearwise without the aforementioned problems.
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