Worn out T-case chain

[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]

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.

[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]

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.

[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.

[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.

[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]

i saved this link after someone posted it ,never used them but they do have a listing ,might be worth a call, i know when this was posted a few years ago people were amazed how expensive the chains were then

http://www.drivetrain.com/parts_cata...se_chains.html

Didn't work... they don't have it.

[nando]

that's the answer then. the only source is BMW.

[z122643]

that's the answer then. the only source is BMW.

well, that sucks.

[ghatid]

well, that sucks.

Fitting signature. I just went ahead and bit the bullet and paid for a new VC. I have 2 tcases with bad VCs, hopefully one of them has a decent chain/sprocket set.

[AndrewBird]

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.

With inserted cutters, just about anything can be cut these days. At my last job, we used to make some parts out of D2 Tool steel. Inserted cutter went through it like butter. We even cut tungsten a few times.

[The Dark Side of Will]

If there's an OTS narrow chain of which iXers could use two, I have the capabilities to do the machine work on the sprockets.

[nando]

here's a quote from my email source:

The snowmobile chains were used on Polaris and Arctic Cat - 3/8” pitch, 68 pitches, ¾ “ wide

I googled - “68 pitch polaris chain”

maybe we can find a part #.

[The Dark Side of Will]

Thanks!
For the record, the BMW chain is 1 3/4" wide.

More info:

According to ZF, SAE Transmissions built the T-cases for ZF. Searching that gives a bunch of eastern European looking websites.

I guess SAE bought the chain from Borg Warner.

Also, the HV015 chain used in Jeeps (NP119, 229 and other T-cases)
3/8" pitch, 98 pitches, 1 3/4" wide (just like stock BMW)

Edit: More stuffs:

BMW 325 I 4WD Pre 1988 HV-024 3/8 Pitch x 1-3/4 W x 68 Pitches - RJ
Straight Pitch (All rounded Link Backs)
BMW 325 I 4WD 89-90 HV-024R 3/8 Pitch x 1-3/4 W x 68 Pitches - RJ
Random Pitch, Rounded & Square Link Backs

From http://www.rsgear.com/catalogs/borgwarnercat-2007.pdf (Hy-Vo chain catalog 2007)

Borg Warner rep was pretty sure that the HV-024 and HV-024R are interchangeable and the difference only has to do with the BACK sides of the links, and only affects operating noise.