Gearbox swap in an 11BL

[KiwiPete]

I'm slowly stripping my 11BL in preparation to swap the motor for an ex Nissan Leaf EV motor. I've read about how weak the Citroen gearboxes are and so I'd like to avoid using it. I'm hoping for ideas/inspiration on an alternative.

I've spoken with Ringer about his R16 box, but they're harder to find here in the US. I figure I should look for something plentiful.....
The modern equivalent of the R16 could be a Subaru transaxle, but I believe they spin the wrong way. I have seen you can get a different gearset to change this, but they're big money.

Trading Estate mentioned he'd seen one with a VW transaxle. Does anyone know of this conversion? Any pics/tips? SoCal has a long history of VW speed shops and modifications so this could be a good option if it will fit.

I should add - to be clear - swapping the motor frees me from having to match the Citroen bell housing bolt pattern. I can look at any N/S oriented transaxle that spins the right way.

Pete

 

[Ken W]

Maybe a 4 speed ID or DS gearbox would be an easier swap.

Cheers, Ken

 

[DoubleChevron]

He will need to make driveshafts either way with a different gearbox. If the traction gearbox is in good condition, I would just use it. You're not going to be putting shock loading into the gearbox as the clutch will never be used. You would just put the car in 2nd or 3rd gear and reverse the motor to go backwards.

I'd use an ID19 gearbox if you wish to modify and fit modern driveshafts

If your making new driveshafts, hit the forums on electric motor conversions and find out what gearboxes people are using. And use the most readily available/cheapest option. You want to find what fits the electric motor the easiest (not what fits the citroen bell housing the easiest).

 

[Rally]

Do you need the gears ? could you use something like a 504 diff and bolt your EV motor to it .
The 504 inner CV would be fine just find some modern outers and the drive line would be inderstuctable .

 

[DoubleChevron]

Do you need the gears ? could you use something like a 504 diff and bolt your EV motor to it .
The 504 inner CV would be fine just find some modern outers and the drive line would be inderstuctable .

Oh.... just get an american independent rear suspension diff/setup .... make the driveshaft outers and your away. something like a simple 9" diff would allow for endless ratio changes in the diff. You could even use a two speed diff (town and country gearing)

 

[citroenthusiast]

Oh.... just get an american independent rear suspension diff/setup .... make the driveshaft outers and your away. something like a simple 9" diff would allow for endless ratio changes in the diff. You could even use a two speed diff (town and country gearing)

Or maybe the front diff from a four-wheel drive? That way you would be driving mostly on the drive side of the crown wheel as opposed to driving on the coast side (as you would be using a rear diff on the front).

 

[KiwiPete]

Maybe a 4 speed ID or DS gearbox would be an easier swap.

Cheers, Ken

I've thought about this. They're not super common over here and the ID gearbox would require some additional machining of the output flanges to fit in the cradle. If I'm going to do any significant modification then I'm hoping to find something a bit more common. The EV motor has a lot more torque than the earlier engines. I'm planning on running it at lower power settings, but I'd like to have spares readily available (and cheap) for when I break something.

 

[KiwiPete]

He will need to make driveshafts either way with a different gearbox. If the traction gearbox is in good condition, I would just use it. You're not going to be putting shock loading into the gearbox as the clutch will never be used. You would just put the car in 2nd or 3rd gear and reverse the motor to go backwards.

I'd use an ID19 gearbox if you wish to modify and fit modern driveshafts

If your making new driveshafts, hit the forums on electric motor conversions and find out what gearboxes people are using. And use the most readily available/cheapest option. You want to find what fits the electric motor the easiest (not what fits the Citroen bell housing the easiest).

You're right. I don't need to fit the Citroen bell housing. The tricky bit is to find a North/South gearbox/transaxle that will fit in the cradle of my 11BL so that the drive flanges will clear. I've got about 9 1/4" across the flats.

Its not a common layout. I think the VW gearbox will work, but I was hoping someone might have done it before and have advice. I am looking for a cheap one locally that I can use to get measurements off.

 

[KiwiPete]

Do you need the gears ? could you use something like a 504 diff and bolt your EV motor to it .
The 504 inner CV would be fine just find some modern outers and the drive line would be inderstuctable .

John:
Or maybe the front diff from a four-wheel drive? That way you would be driving mostly on the drive side of the crown wheel as opposed to driving on the coast side (as you would be using a rear diff on the front).

The leaf motor doesn't have a multi speed gearbox, but it does have reduction gearing between the diff and the motor output. Final drive is about 7.94-8.19 depending on the model year. I figure I will need reduction gearing of some sort before the diff......

I have thought about taking a "Quick Change" rear end and flipping it. They're popular with Hot Rodders. The primary issue here is that the gear would be driven the wrong way, as John mentioned above. These also use straight cut gears for the reduction which would be noisier.

 

[gerrypro]

Renault 16 box?

 

[KiwiPete]

Renault 16 box?

Thanks Gerry.
The R16 box would be a good option. I spoke with Ringer a while back and he has one in his Light 15 - so I know it'll fit.

The problem is that they're not super common over here. (USA). I could probably hunt one down, but I figure if I'm going to the effort of a complete swap then I should aim for something readily available.

Last night I bit the bullet and bought a 1968-1972 VW IRS transaxle. Not the one below - but same model. Its a couple inches longer than the TA unit but I think it will fit.

Once I get done removing the TA cardan shafts this weekend I'll sit it in and see. Pics to follow.

 

[citroenthusiast]

Any chance you can swap the ring gear side to side? If not, they you will be pulling a Colin Chapman. He used the Citroen SM transmission in the Esprit but ran it backward so the pinion was driving the coast side of the ring gear most of the time. It was enough to get past the warranty period but didn't work out very well in the long run.

 

[KiwiPete]

It is possible to flip the ring gear on the VW transaxle - but I don't believe I need to.

The bug has the same motor->trans->direction of movement orientation that the TA does - they just stuck it in the back.

Wasn't the Esprit issue caused because they took the forward facing Citroen transaxle and rotated it so it was hanging out the back?

 

[citroenthusiast]

Is the EV motor going to be in front of the transaxle or behind? Is the VW engine in front of the transaxle or behind? The Esprit problem was mainly because the engine spun the opposite direction from the SM engine so the easy thing to do was to put the engine in front of the transaxle and run the transaxle backwards. The Maserati Merak also uses the SM transaxle but the engine spins the same way, so they hung the transaxle out the back but flipped the ring gear so, even though the final drive was going backwards, everything else was spinning the correct direction inside the transaxle and the pinion was driving the drive side of the ring gear most of the time.

 

[KiwiPete]

The VW engine sits behind the transaxle, same orientation as the TA.

I'm planning on keeping the same orientation - just move the VW transaxle to the front axle. I'll keep the electric motor behind the transaxle, in the engine compartment. Plenty of room in there now.

 

[KiwiPete]

Here is the VW trans beside the TA unit. They're pretty close. The bug unit its a little longer in the nosecone, but I think I can use a cable shift attachment to take about 4" off the nose.

Its about 1 1/2" wider across the drive shaft flats. Hopefully I'll have the TA driveshafts out this weekend and I can drop it in for comparison.

 

[baldrick56]

Just a thought - is there room in front of the axle line for the electric motor? ie sitting about where the guts of the standard box usually sits? The electric motors I've seen aren't that large, plus it would get a nice flow of cooling air in that location. Also more room for the batteries behind the axle. That way you could use a number of the previous suggestions eg Pug 504. If that won't work the VW Beetle transaxle's a good strong unit & should easily handle the extra weight.

Not entirely unrelated - I'd recommend swapping as many of the 'bolt on' body panels for GRP versions as you can - as someone once remarked to me "a Light 15's only Light until you have to push it"

Regards,
Rob

 

[KiwiPete]

From what I've read, Its not advisable to drive the diff directly from the electric motor. Most electric cars have a reduction gear in the transaxle so they end up in the ~7.9-8.2 ratio. The diff by itself is ~4:1 ish...

I got the front end stripped down enough so that I could drop the VW transaxle in place. I'm starting to think that this will fit! I can loose about 4" from the front by switching to a different style shift mechanism.

I'll need to open the cradle a little to clearance the drive flanges - but not much. I figure I can plate over what's left to compensate.

 

[citroenthusiast]

For the drive shafts are you going to weld some VW joints to the TAV shafts or are you going to put the TAV flange on the VW transmission? Pretty sure most driveline shops could do that for you. How are those silentblocs on the lower suspension arm? Now is the time to change those out if they are dodgy....

 

[KiwiPete]

For the drive shafts are you going to weld some VW joints to the TAV shafts or are you going to put the TAV flange on the VW transmission? Pretty sure most driveline shops could do that for you. How are those silentblocs on the lower suspension arm? Now is the time to change those out if they are dodgy...

I'm going to take a leaf out of Johns book (Ringer) and upgrade to disc. Not certain what donor yet but probably the same Holden Astra (Opel/Saturn Astra here in the US) that he used. With the extra weight of the batteries I'll feel better with improved brakes.

I'm still not decided on whether I'll keep the TA wheels -- but most likely.

Re the silentblocks -- I'm assuming they're dodgy and am planning on replacing them. I'm getting the Harbor Freight 20 ton press this weekend. I saw your post on another thread and I'm hoping mine will go smoother........