RWD reduction box

[SciroccoEV]

I've been considering using the first reduction stage of the Leaf gearbox as the basis for a rear wheel drive gearbox.

It appears that the gear driven from the input pinion is splined to its shaft, so it should be relatively simple to machine a new output shaft for it.

I'm hoping that the ratio changes between the Gen 1 gearbox and the Gen 2 were achieved by shifting the pitch diameters and the shaft centres are identical.

Gen 1 gears 17:31 / 17:74
Gen 2 gears 17:32 / 17:75

At the moment I have a Gen1 gearbox, but the Gen2 ratio looks a better match for my 4.1 final drive.

[zippy500]

I have some of the internals of a gen2 box if they are the same

[SciroccoEV]

I have some of the internals of a gen2 box if they are the same

I'd certainly be interested in the input and second gear shafts.

[zippy500]

parts I have.

Send me a PM if your intrested

[StenOrl]

Hi
do you sell a conversion from a Leaf motor to a transmission?
I have a Leaf EM57 motor, but there is no transition

[SciroccoEV]

do you sell a conversion from a Leaf motor to a transmission?

No, I don't.

I'm looking into the idea of using parts of the Leaf transaxle to make a reduction drive to replace the original gearbox in rear wheel drive vehicles.

Thanks to zippy500, I have a set of gears and as I thought, the intermediate shaft input gear is splined and can easily be removed.

I'll have to make a new shaft, splined to take the gear and a new housing, but I think this will work as a RWD reduction drive.

Ratio is 32/17 or 1.882:1, which should work OK with the 4.1 diff ratio in my Lotus. That's taller gearing than the Leaf final drive, but the rolling radius is a little smaller too.
Leafs with the EM61 motor have slightly taller gearing of 31/17 or 1.824.

[Tremelune]

This would be to replace something like the $3,000 2:1 TorqueBox?

How would the motor -> gearbox -> driveshaft coupling work?

[SciroccoEV]

How would the motor -> gearbox -> driveshaft coupling work?

The Leaf motor would connect to the gearbox via the original input spline and gear.

I haven't decided the output, but I may just replicate the standard Toyota W58 sliding spline for my use in the Lotus.

[Tremelune]

Anything that would replace the $3,000 TorqueBox would be sweet. It's already painful to mate a Leaf motor to a manual gearbox, and then you're dragging all that around...

[Bratitude]

SciroccoEV, any more development here?

I’m in the process of making some 930 stub flanges for the leaf gearbox, next phase would be halving the gear reduction to something more along the lines of 4:1 for rwd/ 4wd applications.

[SciroccoEV]

SciroccoEV, any more development here?

I’m in the process of making some 930 stub flanges for the leaf gearbox, next phase would be halving the gear reduction to something more along the lines of 4:1 for rwd/ 4wd applications.

Very little progress at the moment. My Scirocco was meant to go to a local vehicle restoration business, but lockdown disrupted that plan and I'm doing the restoration myself, so the Lotus Excel conversion has barely been touched. I have talked to a couple of friends about exactly how to tackle the gearbox and both have been very encouraging. One used to make replacement internals for the infamous Lotus "Queerboxes" and the other specialises in running transmission simulations (mostly for OEM EV projects these days), so I have pretty good sources.

[Bratitude]

Hey has one one confirmed if the gen1 vs gen2 gearbox’s gear centre's are the same and just the gear pitch is different?

Paul did the gen2 gears fit in the Gen 1 box?

[SciroccoEV]

Hey has one one confirmed if the gen1 vs gen2 gearbox’s gear centre's are the same and just the gear pitch is different?

Paul did the gen2 gears fit in the Gen 1 box?

Still not confirmed, but it would be standard practice. The gear pitch and diameter would be the same and a technique called profile shifting used.

[stuartd]

I’ve been working on this and had some ideas use the original gearbox case bit bulky I know
But it’s already there I’ve machined off the brush carrier housing for now which gives a flat area to bolts to adapter plate to bolt to gearbox transfer box whatever you need
The output shaft needs to be bigger and longer I’m going for 35mm in diameter bought a 72 x 35 x 17 bearing to go on the output end of the shaft that’s coming
And I’m trying to get my head around machining double spline shaft to go from the inner gear to output splines
Going to do a video on this hopefully out middle of this week

Stuart

[JamesWLG]

I think I might try this reduction gearing idea myself, when I eventually get round the drive line construction.

For calculating the motor offset from the prop shaft, and ultimately if I will have room in the transmission tunnel. What is the distance between the gear shaft centres?

[SciroccoEV]

80mm by Mk1 eyeball

[JamesWLG]

80mm by Mk1 eyeball

Thanks that's really helpful. I think it might just fit.

[SciroccoEV]

I was talking to Chris from Zero EV, about the reduction box they were testing to fit the Hyper 9. The first example was similar to the Torque Trends gearbox, but the epicyclic design was too noisy and generated too much heat. They've now found an existing reduction gearbox design that they could have modified to make it suitable for EV applications. It's officially rated at 280Nm, but Chris thinks it can take a fair bit more and said the cost was about £1600.

With a different coupler and adaptor, it could be mated to a Leaf motor.

[JamesWLG]

I just heard about this myself. It definitely sound interesting and they have two ratio options 2:1 and 1.75:1

[Bratitude]

I got adapter plates with the NEMA b face pattern, so that’s covered.
what’s the coupler look like?

This looks like the tail end of some transmission

[JamesWLG]

I've emailed them for more info on this and one of their new motors.

It probably is an adaptation of a transmission output. And there could be some sort of changeable coupler in there as the hyper9 and their new motors have different shafts.

I'm hoping it has a speedo drive also.

[JamesWLG]

After an overly long email chain I have some info in the ZeroEV gearboxes and Zonic motors. Let me know if you are interested and I'll share.

[remy_martian]

Yes. Please spill the beans on that reducer.

[Bratitude]

After an overly long email chain I have some info in the ZeroEV gearboxes and Zonic motors. Let me know if you are interested and I'll share.

Yes, what tail section is this from what is it? Who makes it?

[janosch]

We have punched a hole through the Leaf gearbox, so we are not using its differential and connect the middle cog to the taxi differential.

This made us end up with about a fixed 8:1 reduction which has held very well for more than a thousand miles now.

I am not very mechanical, they talked a bunch about the oil in it, and something about brushes and seals but that is all solved it doesn't leak.