Shortening or modifying CV axles and how to do it?

[Zieg]

I'd like to talk about the matter of shortening/modifying CV axles and what options are out there. I think it's a common enough issue encountered during conversions, so I'm hoping there will be a few people here with different insights.

I'm aware of three possibilities:

1. Welding. Either to shorten the axle or to Frankenstein two different axles together. Various methods out there to try and keep them as strong and straight as possible, but often strength and straightness are questionable. Might (Probably?) require a TIG welder.

2. Machining. Cut the splines off one end and machine new splines as needed. Requires a mill, rotary indexing table, an appropriate cutter and knowledge of the specs of the spline you need. May be hampered by the hardening of the axle, as well as whether the diameter of the shaft at the new location is large enough to machine the splines.

3. Custom axles. Take measurements and order a set custom made. In my experience, a set of shortened Leaf axles was quoted at $2000 USD, plus they wanted to re-use the inner joints. They were not willing to provide the shafts on their own.


Are there any other options out there worth looking at. What did you do on your conversion?

[arber333]

I'd like to talk about the matter of shortening/modifying CV axles and what options are out there. I think it's a common enough issue encountered during conversions, so I'm hoping there will be a few people here with different insights.

.....
Are there any other options out there worth looking at. What did you do on your conversion?

Well i will soon go with the No. 1 option - welding on Mazda MX3 reconversion .
viewtopic.php?t=4210
With converting Peugeot i was fortunate enough the Pug axles were larger than Leafs and hollow. This allowed me to cut the axles a bit longer and put them to lathe. Some material later i could slide Leaf axle into the Pug larger axle and weld it around the joint.
HOWEVER! This by itself is not enough. By material joining theory those welds will cause stress in a form of torque spike which could damage material, Usually welded axles are normalized in an oven at more than 400degC for a long time. I imagine this is why custom axles are expensive.
My idea however comes from aviation instruction on how to extend shafts and carry members.

https://grassrootsmotorsports.com/forum ... 977/page1/

Idea is to fit a sleeve over the innitial weld. This sleeve will be welded at the ends of course. But additionaly i will put several holes into that sleeve spaced at 25mm and at 90deg to each other. Then we will rosette weld those.
This effort will mean that the torque spike will not happen as rosette weldswill join material so it will only create a wider torque hill instead of a true shattering spike in place of weld.

That is theory at least. I need to put it to practical application...

[jrbe]

There's a few links in this forum of different axle manufacturers. I think this was one,
https://www.pacificcustoms.com/porsche- ... axles.html

You can use Google site search to find a few more.
(Custom axles Site:https://openinverter.org/forum/) in the search window.

[Bratitude]

I just made stub shaft adapters for the leaf and outlander gearbox, so any German style cv joint can bolt up (90mm, 100mm, 108mm)

In which you can buy a large variety of different axle shaft lengths for.

[arber333]

I just made stub shaft adapters for the leaf and outlander gearbox, so any German style cv joint can bolt up (90mm, 100mm, 108mm)
In which you can buy a large variety of different axle shaft lengths for.

Yes i was thinking of using your design but in the end Mazda has huge steel construction for suspension arms pivot directly next to gearbox. That would interfere with shafts and gearbox positioning. I have to make axles as thin as possible.

[Zieg]

I just made stub shaft adapters for the leaf and outlander gearbox, so any German style cv joint can bolt up (90mm, 100mm, 108mm)

In which you can buy a large variety of different axle shaft lengths for.

I saw those, just wasn't sure how to adapt the other end back to the Leaf hubs?

[arber333]

I saw those, just wasn't sure how to adapt the other end back to the Leaf hubs?

You would need to make the mirror flange with some taper for mechanical connection or ust weld it on the other axle...

[Zieg]

Hmm, not quite sure what you mean by mirror flange, but if you're taking about making a new splined shaft to go through the hub, it sounds like it would be easier to just machine the oem shaft as in option 2.

As for welding, if I'm welding stuff I may as well just cut and weld the OEM shaft, right?

[arber333]

Hmm, not quite sure what you mean by mirror flange, but if you're taking about making a new splined shaft to go through the hub, it sounds like it would be easier to just machine the oem shaft as in option 2.

As for welding, if I'm welding stuff I may as well just cut and weld the OEM shaft, right?

No i meant you would make(or buy) another flange to fit on to your OEM car side. You can cut mechanical connection(spline, dowel etc...) but i think it is easier to weld the flange onto the OEM shaft side. Both flanges are bolted together and you have effective bolted coupling.

[Zieg]

Oh gotcha. Yeah I don't think that's really feasible with the Leaf axles due to how they are built. Would have to be welding to the middle shaft and then I'm still back to option 1.

[Bratitude]

You guys are mixing up terminology and it’s making it really confusing.

Axle, joint, flange, shaft, doj, etc.

Zieg what exactly are you trying to do?

Sounds like you are using the Nissan leaf knuckles but need longer axles?


My stub shaft adapters are for flange based cv joints, ie where the cv joint bolts onto a flange that then connects to a gearbox.

The stock leaf cv joints are not flange based. The are all in one.


What arber is saying is, you take the outer cv joint, mill it down and weld a flange into it with a 100mm or 108mm bolt pattern, then 100mm or 108mm cv joints will bolt to it. With my leaf stubs on the other end and a 100mm or 108mm flange, you can use off the shelf cv joints and axle shafts.

In your case if you using the leaf gearbox and leaf knuckles, a longer leaf axle shaft would be the way forward. It would just take it to the axle place everyone uses and get them to cut you a custom one.

[arber333]

Oh gotcha. Yeah I don't think that's really feasible with the Leaf axles due to how they are built. Would have to be welding to the middle shaft and then I'm still back to option 1.

In my first instance i did just that. And luck had it that Peugeot axles were hollow in that section and Leaf axles were much thinner. So i brought them to a friend who put them to lathe and skimmed a bit of surface from leaf stub and some inner surface from peugeot tube so that both fit into one another. Then we welded them. The greatest problem was cutting holes in peugeot axles for rosette welds. That is some tough material!
EDIT: Because of that you need to use similar adjacent material as well. Not just some off the shelf steel but proper CrMo steel...

[Zieg]

Yeah, I'm using leaf hubs in a custom knuckle, though I need the axles shorter, not longer.

I called the two biggest local shops months ago and they said they don't do any custom work on CVs. Last night I scoured the Locost forum and found this place, looks like they can do what I want!
https://dutchmanaxles.com/services.html

[P.S.Mangelsdorf]

When I first build my Tesla swap, I cut and welded the Tesla axles to the GTO axles my rear suspension uses. I used a technique I saw on Youtube of cutting each axle on an angle, then welding, then sleeving and welding again. That worked for getting on the road but eventually failed, and it had bad vibrations the whole time too.

I then used the ZeroEV Tesla to 930 adapter flange, and built axles using 930 CV joints and custom length axles I got from a dune buggy supply place online. That's the benefit (at least in North America) of switching to 930 type CV joints - there is a ton of support thanks to off-roaders using the same joints and thus needing all sorts of axle lengths with that spline design.

[Zieg]

How did you mate them to your outer CV joints?

[P.S.Mangelsdorf]

How did you mate them to your outer CV joints?

The GTO hubs actually use 930 style CV joints as well.

[arber333]

When I first build my Tesla swap, I cut and welded the Tesla axles to the GTO axles my rear suspension uses. I used a technique I saw on Youtube of cutting each axle on an angle, then welding, then sleeving and welding again. That worked for getting on the road but eventually failed, and it had bad vibrations the whole time too.

......

Well first of all you need to weld the seams like you did. Then you prepare the sleeve. It needs to be made of correct material that allows for good normalizing in air and has high strength when quenched. First you need to drill 8mm holes with about 25mm spacing in 90deg positioning. They will serve to weld rosettes in material underneath in effect fusing sleeve to both shafts. Of course you need to weld the sleeve on both circumferences.
Then i suggest you normalize steel according to material properties chart... basicaly heat-up material to certain level and letting it cool down by air.
Finally you need to put that shaft to lathe and balance it in the plane of rotation.

Like i said Mazda has huge chassis scissors in front which can interfeere with size of the driveshaft. I need to keep the size down.

[P.S.Mangelsdorf]

Well first of all you need to weld the seams like you did. Then you prepare the sleeve. It needs to be made of correct material that allows for good normalizing in air and has high strength when quenched. First you need to drill 8mm holes with about 25mm spacing in 90deg positioning. They will serve to weld rosettes in material underneath in effect fusing sleeve to both shafts. Of course you need to weld the sleeve on both circumferences.
Then i suggest you normalize steel according to material properties chart... basicaly heat-up material to certain level and letting it cool down by air.
Finally you need to put that shaft to lathe and balance it in the plane of rotation.

Like i said Mazda has huge chassis scissors in front which can interfeere with size of the driveshaft. I need to keep the size down.

Yeah, that's all correct. After doing it both ways (welding and building with adapter flanges), I would absolutely recommend building it the right way with adapters if necessary.