1356 Doubler, It's like Bigfoot

[KrazyKarl02]

Bigfoot, many people claim to have seen him, but no one really has an entire big foot alive. This is just like the BW1356 Doubler.

I would like to discuss making a doubler with a 1356 in the front and a 205 in the back.

For those who do not know, the BW1356 transfer case was put behind just about ever full size ford truck from the late 80's until 1996. It went in 1/2 tons, 3/4's and 1 tons. If you go to any decent junk yard you are going to trip over a few. They offer a low range of around 2.6:1 (better than a 203 or 205). So end of the day, they seem to be a reliable case that you can find anywhere, say like my back yard, where you will find 2.

You here about people making doublers out of them, but why do you not see more of them? Why does DD or Novak not make a kit?

First bigfoot rumor: The case will light on fire when you cut it - It does not, there are lots of people on the internet who have cut and sealed them

[bcolman]

dd machine or something like that made a kit at one point, along with the np241 kit, i would search pirate and see if he is still making the kit

[KrazyKarl02]

Second Bigfoot issue: I have seen where some people stick a BW1356 to a 205 as they have the same output shaft/input spline. This makes a giant long doubler. This is a great solution if you wheel a stretched limo.

The rest of the people I have found on the internet do some dumb ass thing where they cut the shaft, make an interference (force) fit, jam them together and then weld them, and then put them in liquid nitrogen, followed by pissing on them, like this guy:

http://pirate4x4.com/forum/showthrea...83#post6683383

Others talk about re-splining the shaft themselves. From what I understand this is a giant pain in the ass. Krebs kind of touched on it here in his Doubler thread, which is a good read because I threw in some classic Chuck Norris Jokes

http://www.tamor.org/forums/showthre...hlight=doubler

WTF? Moser will respline a shaft for $65.

http://www.moserengineering.com/Page...pservices.html

Look it up, Scott did it and wrote about it on this board. Why would you do an interference fit, etc... when for $65 it's done and done right? Does "cold machining" mess up the heat treat? Are these shafts just case hardened and not through hardened?

[KrazyKarl02]

Finally, every time you find something on the interweb about it, the guy has taken the case apart, taken pretty pictures of the shaft, debated about how to weld the shaft, and finally gotten busy and forgotten about it.

[KrazyKarl02]

dd machine or something like that made a kit at one point, along with the np241 kit, i would search pirate and see if he is still making the kit

As I understand it D.D. Made one for a 1350, but never a 1356

[Doug Krebs]

My NP241 was only hardened on the surface. I believe most of these shafts are induction hardened.

I chopped a slice off with the EDM and then did hardness tests across the cross section...

Edit: other than lining the cases up, the intermediate shaft is the only real big pain in the ass.

Doesn't your dad have a dividing head? That's the real key for splining.

[KrazyKarl02]

So here is my basic plan. Shoot holes in it please:

Step one: Take apart 1356 and "mock it up" with a 205. A little bit of distance in between to allow for shifting the 205.

Step two: Send the 1356 shaft to Moser, cut it long enough so as not to get into the hollow part of the 1356 shaft.

Step three: Take a 5" piece of pipe from work (essentially free), turn the OD and make a step in the ends with my old man's lathe

Step four: Make two "bolting faces" with my old man's lathe. Make a step on the ID of the bolting face to match previously mentione pipe. This way it will be in line

Step five: Weld it together

Step six: assemble and done.

Why would this not work?

[KrazyKarl02]

My NP241 was only hardened on the surface. I believe most of these shafts are induction hardened.

I chopped a slice off with the EDM and then did hardness tests across the cross section...

Edit: other than lining the cases up, the intermediate shaft is the only real big pain in the ass.

Doesn't your dad have a dividing head? That's the real key for splining.

So when you did a hardness test did you notice a change in the center?

Dividing head, you mean indexing head, then yes. Bill also has a spline cutter, but for $65, I think I would rather pay someone.

[Doug Krebs]

Dividing head/indexing head are synonymous with each other... Don't go all David on me here.

The hardening was only ~.015 past the surface... I really didn't see a way of using the old 241 shaft.

Why reinvent the wheel? I'd copy the DD machine/rocks box one and use the aluminum case. That way you really only need to make a couple adapter plates.

[KrazyKarl02]

Dividing head/indexing head are synonymous with each other... Don't go all David on me here.

The hardening was only ~.015 past the surface... I really didn't see a way of using the old 241 shaft.

Why reinvent the wheel? I'd copy the DD machine/rocks box one and use the aluminum case. That way you really only need to make a couple adapter plates.

I have seen some posting where people say the 1356 and 205 have some clearance issues, so you have to put a little more room in between them. Other than that the 1356 shaft is hollow to a point for lubrication. The 1356 shaft has to be a little longer so you do not cut the new splines into the hollow portion (making it weaker). All of this is from the interweb.

I think the stub shaft is the hard thing to do here, I just can't figure out why more people don't send it off to Moser and be done with it.

[Doug Krebs]

I think the stub shaft is the hard thing to do here, I just can't figure out why more people don't send it off to Moser and be done with it.

I agree that it's easy to send it off and have it done. I guess my point was, do they heat treat the shaft again? I don't see how there will be any strength without it unless the 1356 shaft is heat treated differently than mine.

[robertf03]

this idea would probably work well in a solid axle explorer

doug do you have access to the heat treating stuff in the room behind where you sit on tamor all day?

[Doug Krebs]

this idea would probably work well in a solid axle explorer

doug do you have access to the heat treating stuff in the room behind where you sit on tamor all day?

we have 2 furnaces... they should be able to fit a shaft just fine. I've never measured the length, but I'll guess around 20". They are not vacuum furnaces. Although, one has a port on the rear where you can hook up gas...

One guy warned me that warping could be an issue. We could easily test a piece. I also know where a tool post grinder is... I planned on messing around with this at christmas time.

[robertf03]

there was some guy trying to hook an nv4500 up to a rover case and novak made a new shaft and hardened it.

[KrazyKarl02]

I agree that it's easy to send it off and have it done. I guess my point was, do they heat treat the shaft again? I don't see how there will be any strength without it unless the 1356 shaft is heat treated differently than mine.

I guess what guys like D.D. Machine do is cut the shaft then re-heat treat it? I know he had an option where you could send in your current shaft and he would cut it down.

Side note, Scott had an axle shaft resplined by Moser. I don't think it was heat treated after the machining and I am guessing it is still working. So why would that work and not this? Is it because you have to take too much material off and get out of the outside hardened area?