# Rear differential/axle motors



## 67BGTEV (Nov 1, 2013)

This is great news. Cost may be a concern for DIYers, but at least we have a option.


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## brian_ (Feb 7, 2017)

You can wander through the Dana Electrified e-Axle range, but they're really not targeting light duty road vehicles - off-highway industrial vehicles and medium-duty to heavy-duty on-highway trucks and buses are more typical.

One reason that there are few options of this type (an electrically powered beam axle) in this weight range is that consumer electric trucks and heavy SUVs are going to fully independent suspension at the same time as going electric.

The thing that is disappointing about most of these is that they use a single motor and a differential. Especially in larger sizes, it is more functional and quite practical to use two independent motors; the ZF AxTrak AVE system has two motors (although it has them to allow an inverted portal design for a low-floor bus), and so does one of the e-drive axles from BYD (the Chinese maker of battery-electric buses and trucks).

If it ever actually goes into production, the Tesla Semi is expected to have (and had in the PR prototype) beam axles with independent left and right motors from the Model 3 on each axle.


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## catamounts (Oct 28, 2020)

brian_ said:


> You can wander through the Dana Electrified e-Axle range, but they're really not targeting light duty road vehicles - off-highway industrial vehicles and medium-duty to heavy-duty on-highway trucks and buses are more typical.
> 
> One reason that there are few options of this type (an electrically powered beam axle) in this weight range is that consumer electric trucks and heavy SUVs are going to fully independent suspension at the same time as going electric.
> 
> ...


If I'm not mistaking, both Rivian and Lordstown Motor's consumer trucks will be using independent motors. Obviously not a DIY-ready solution yet, but it seems to be catching on. One thing to consider is the cost and weight of multiple motors vs. one motor and a differential.


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## brian_ (Feb 7, 2017)

catamounts said:


> If I'm not mistaking, both Rivian and Lordstown Motor's consumer trucks will be using independent motors. Obviously not a DIY-ready solution yet, but it seems to be catching on. One thing to consider is the cost and weight of multiple motors vs. one motor and a differential.


Yes, among the coming or proposed light trucks, Rivan is showing a motor and gearbox unit per wheel, and Lordstown is showing hub motors (which is how we know the Lordstown truck won't actually be built). In the GMC Hummer EV, the rear has separate motors per wheel and the front has a single motor.


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## brian_ (Feb 7, 2017)

brian_ said:


> ... Lordstown is showing hub motors (which is how we know the Lordstown truck won't actually be built).


Lordstown was planning to use Elaphe motors. As expected, they have crashed and burned, so they are not and will not be an example of successful hub motor application.
Lordstown Motors falls apart


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## shackf16 (Jun 13, 2021)

I've been looking into these kind of options to "hybridize" my current FWD vehicle. I looked into different hub motor options (Elaphe, Proteon, Orbis - none seem feasible currently) as well as e-Axles from larger manufactures (but only available to OEMs?). My current plan is to retrofit an entire Model 3 rear suspension in place of the existing unpowered rear suspension and add a smallish battery pack (about 15kWh) in the cargo area. If I can figure out how to control the electric motor in combination with the IC engine, then this will make for a pretty awesome setup that will make tons of power as well as improve my fuel economy up to about 60 MPH when the electric motor will cut off. I've seen several Model S rear suspension installs, but the track width is much wider than my current vehicle, and I don't need a large drive unit level of power to accomplish my goals. In the future I may do a full EV conversion on this vehicle and add another small front drive unit and much larger battery pack, but for now the PHEV is enough of a challenge.


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## brian_ (Feb 7, 2017)

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