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4x4 truck - motor coupling choices.

954 Views 5 Replies 5 Participants Last post by  D&VsEVJeep
Hi all,

I've finally decided that I want to build an EV. I thought it would be awesome to use a light-duty pickup, so I scooped up a 1982 Datsun 720 4x4 on the cheap. I was hoping to retain the 4X4 capability, but this particular truck is already on the border of too heavy to convert. (~3,000 lbs pre-stripped).

The truck has locking hubs and a separate gearbox/shifter for the 4X4.

I'm still researching the specifics of how the drivetrain works, so please forgive any stupid questions.

Where would you couple a motor to?

Initially, I was thinking of using the existing transmission, but if I could shed that weight it would be good. Also, the transmission likely needs rebuilding, so there's another reason to ditch it. I've read that a 2-speed gearbox is a decent solution, but I'm not sure how applicable it is in my case.

Seems to me that my choices are:

- Keep existing transmission - CanEV does sell an adapter plate, simple solution with extra weight.

-Couple directly to the driveshaft before it hits the 4X4 gear-box. Mount the motor where the transmission was. Leaves the engine compartment open for batteries. Keeps the 4X4 option.

- Drop the 4X4 option and drive the rear wheels directly using or replacing that 4X4 gear box. The gear ratio is probably all wrong and I'd likely put a 2-speed transmission there. This would shed the weight of the front drive shaft and transmission.

- Sell this truck and buy a light-duty mid-80's toyota.

Any help is much appreciated.
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· Registered
5,395 Posts
Reminds me - I have one in my late father's barn with 13,000 miles on it. Engine died 1,000 miles out of warranty...P.O.S....I made the mistake of using it like a truck (those early ones had car engines in them).

Next time I'm out there (it's 2500 miles from me), I'll need to go in to see if anything is left, rustwise. Never thought about EV converting it now.

· Registered
180 Posts
A friend has rwd 720 diesel with an sd22. Great little truck. Once we finish tidying up the rest of the truck were dropping a leaf motor in it.
Im working on a replacement gear sets for the leaf gearbox, enabling the leaf gearbox to be used as transfer case. I’ll be mounting an r180 diff upfront making it awd.

im preaty sure the 4x4 720 has a divorced transfer case, so driving that directly may be a good option. But that depends on what the final drive ratios end Up being.

I’m too busy developing leaf parts for production, but I’d love to pickup and test a ls600h hybrid transmission. It’s the awd variant of the gs450h hybrid transmission. it would potentially be an ideal candidate, leaves the engine bay empty!

· Registered
5 Posts
Discussion Starter · #5 ·
Thanks all. It does have a divorced transfer case. I'll do some digging online and on the datsun forum ( and see if I can find those gear ratios.

In response to electro works: the truck will serve a few purposes.
1.Teach me how to convert a car
2. In-town hauling (there's so much litter out there).
3. If I can manage any to get any decent range, I'll be taking it up to the snow for winter activities. The main motivation for
4. Nostalgia. My grandfather always had a few Datsuns in the front yard he was working on.

· Registered
243 Posts
We are coupling an e-motor that has an integrated speed reducer to the stock transfer case of our Jeep conversion to keep the 2wd/4wd and 4wd low options. Another option is to rotate a Tesla drive unit (either a LDU from a model S or a model 3 DU), replace the differential gearset and add a LSD and mount it transversely and connect the "right and left" outputs to the front and back differentials for fulltime AWD... There is a recent jeep conversion that did this...
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