Worn out T-case chain

[The Dark Side of Will]

Yeah but if they can do a VNT type turbo housing a pin should be able to be made too? :)

As Nando said, the material properties of high tensile steel are WAY higher than what can be achieved with AM, even when printing with metallic fill. The specific properties required are shear strength and surface hardness.

Also, the pins are precision ground, which leaves a MUCH smoother surface finish and more precise final dimensions than any current AM technique can replicate.

Maybe it is the futurist in me, but I am holding out hope that someday we'll be able to print many replacement parts for older cars on our own someday. Time will tell! In the meantime I am very interested for somebody to report back on some of the leads on chain sources mentioned in the thread.

I see the place of AM as being able to economically make small production runs of complex parts (like cylinder heads... or maybe the individual links in the chains) which still require finish machine work... IOW, it's a low volume alternative to high volume manufacturing processes like casting or punching.

The current problem is that even metallic prints aren't very strong.

[The Dark Side of Will]

If we could get sufficient length pins, they could be remade as they still make the links.

Do we know what the diameter of the pins is?
Drill rod and precision ground rod should be readily available in basically any standard diameter.

Are the pins peened?

I was under the impression that the side links were a tighter press fit than the interior links and that was all that was necessary to keep the chain together.

[iXerces]

Great discussion, thanks everybody for your insight. Nando, as I understand your argument and have done a bit more reading about 3D printing (aka "Additive Manufacturing") it seems I have to reluctantly agree that it doesn't seem feasible, certainly for the foreseeable future, at least in this case.

Maybe it is the futurist in me, but I am holding out hope that someday we'll be able to print many replacement parts for older cars on our own someday. Time will tell! In the meantime I am very interested for somebody to report back on some of the leads on chain sources mentioned in the thread.

[nando]

the pins have to take high shear. I don't think printed powder metal is going to be able to do that. the pins are made out of rolled steel wire at thousands of lbs of pressure. the material properties vs a housing (that can be made of cast material) are just fundamentally different.

[Nisse Järnet]

this isn't a turbo housing, it's a hardened steel wire. :p

Yeah but if they can do a VNT type turbo housing a pin should be able to be made too? :)

[nando]

I don't think the chain is being remanufactured but I'm hoping I'm wrong. drivetrain.com is probably worth checking out.

auto and manual transfercases are internally identical.

[z122643]

So my iX has slack in the chain I've been contemplating replacing it with the BMW chain. But the price..

I'm little confused by the mass of information above. Does anyone make a direct replacement chain? And does the chain vary from manual t-case to auto t-case?

[nando]

this isn't a turbo housing, it's a hardened steel wire. :p

[Nisse Järnet]

Koenigsegg 3D prints turbo housings etc so it can be done but its expensive :)

https://www.youtube.com/watch?v=DNedUZxP8NU

[nando]

3D printing is only really intended for prototype parts and no machine that exists today can make full strength parts.

The issue I see with the pins is they are more of a rivet than a pin. You would need to figure out how to peen the end and get the correct tension once assembled, which could take some trial and error.

Seems much easier to me to modify the sprockets to run two chains. All you would need to do is turn a groove in the center of each sprocket for the ends of the chain to sit in.

I think this is possible but the sprockets are hardened which makes machining more difficult. There was a specific chain used in a snowmobile that he thought would work, I'll see if i can dig up the part number.

[nando]

The pins are what take all the drivetrain forces. You can't make them with a 3d printer, they are made from steel wire of a specific grade.

[AndrewBird]

3D printing is only really intended for prototype parts and no machine that exists today can make full strength parts.

The issue I see with the pins is they are more of a rivet than a pin. You would need to figure out how to peen the end and get the correct tension once assembled, which could take some trial and error.

Seems much easier to me to modify the sprockets to run two chains. All you would need to do is turn a groove in the center of each sprocket for the ends of the chain to sit in.

[iXerces]

Has there been a discussion about using a 3D printing approach to replace such NLA items as the pins nando is talking about?

Full disclosure, I know practically nothing about 3D printing nor machining, but from what I understand this might technically be feasible if you could get an accurate copy made. You'd probably have to have the actual metal work/machining being done by some large outfit that specializes in metal 3D printing since in home units only do plastic, AFAIK. What are the other major potential barriers? Maybe it would be cost prohibitive either way, for the moment at least...

Thoughts?

[nando]

AFAIK ZF doesn't sell the chain. they might have some but you can't purchase them without a rebuilt transfercase.

the Prowler guy bought them all from BW and whatever NOS he could find. He was pretty sure he bought all the remaining new chains other than what BMW has. I sold him 2 of my used chains since he couldn't find new ones. we discussed options like replacing the 1 1/2" chain with two 5/8" chains, but that would require modified or custom sprockets.

in any case, even if ZF and BMW have some, they aren't being produced anymore by BW. they only make narrow chains now, because 2x smaller chains are just as strong as 1 wider chain, but they're quieter and more efficient. I think the longest pins you can get are maybe 1" long. If we could get sufficient length pins, they could be remade as they still make the links.

[Nisse Järnet]

ZF didn't make the E30 chain, borg warner did. :)

Aha, shit :)

Did the Prowler guy but up BMW's stock, ZF's or BW's? (Or all of them?)

We tried to cross-reference BMW's part number on ZF's web catalog, but nothing came up.

You have to contact ZF, the numbers aint the same.