Builds Moonshine - A Build Thread (2 Viewers)

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I think the reference is to a part in the transfer case...(I may be wrong)..
 
So it's been 2 days. What broke?? The world wonders!*

I want an Atlas too. Waiting to see if it's the D300 or something more sinister.




*This is a historical reference and no disrespect intended.
 
I hope it's something simple to fix. But it would be disappointing to know the NV4500 transmission could not take trying to pull someone out of the sand. I thought these things were built to tow really heavy loads.

That's what I was telling my club members when it happened. Regardless, it's not the transmission :D

So it's been 2 days. What broke?? The world wonders!*

I want an Atlas too. Waiting to see if it's the D300 or something more sinister.

Ask and ye shall receive!!

Last night I got the case out and on the bench:

20150505_161242.jpg


First thing I did was to verify that the t-case was the problem. I shifted the rear output into low range and attempted to spin the spud and rear output, yet they spun independently. This confirms that the problem is indeed the transfer case :bounce: :bounce2:

I then pulled the clocking ring off to find this:

20150505_162405.jpg


20150505_162411.jpg


Pulled the idler out of the case so I could get the input gear out. The spud shaft snapped so cleanly it almost looks machined!! All of the gears in the case look fantastic, and although I had a couple of metal filings on the little drain plug, I found no other evidence of contamination.

You can see where the splines neck down to the break point, and then the piece widens up for the "collar". It appears to be an unnecessary weak point right there.

20150505_170103.jpg


20150505_170123.jpg


Got everything cleaned up and ready to go back together when I get a new spud shaft :D

20150505_173651.jpg


I'm going to call the company I got this from and ask if I'm putting too much power through this thing, or if I got one from a bad batch or what. Regardless, I will be ordering a new one and having it shipped to me either for tomorrow or for Friday, so that I am back on the road!!
 
Great news. I think I'd order 2 spud shafts.

Which kit was this?
 
JB Conversions spud shaft. I agree, I will be ordering two.

I want to talk to them about whether or not this neck-down was planned or if it was a mistake. I also want to know if I've put too much power through the spud shaft, or if the spud shaft prematurely failed.

I know I've said this already, but I'm depressed that this is the weak point and not my 1310 u-joints. The u-joints are significantly smaller than factory LC joints on purpose. It's much easier to replace a driveshaft, or an output yoke (like last year) than it is to replace a spud shaft.


Along those lines, do you think it's possible that last year's rear output yoke failure somehow caused this spud shaft to weaken?
 
That is a really clean break. I wonder if the rush of torque the 4bt makes had something to do with how clean this broke. Does the market offer stronger spud shafts?
 
That is a really clean break. I wonder if the rush of torque the 4bt makes had something to do with how clean this broke. Does the market offer stronger spud shafts?

Maybe, not sure. The Advance Adapters version looks to have the same neck-down at the collar like the JB Conversions does, so I'm not sure if it's any stronger.
 
I forgot you don't have a split case. What TC are you running?
 
I'm not an engineer, but I did stay at a holiday inn once. To me, this seems like a purposely designed fuse. Better break it there than anywhere else. Still though, isn't that tcase rated to handle a 6bt and its torque?
 
I forgot you don't have a split case. What TC are you running?

Dana 300. Centered rear output, easily clockable, easily upgradeable, heavy duty and relatively compact. I love this case.

I'm not an engineer, but I did stay at a holiday inn once. To me, this seems like a purposely designed fuse. Better break it there than anywhere else. Still though, isn't that tcase rated to handle a 6bt and its torque?

I agree, that's what seems to be the case. I don't want my fuse to be here, I want my "fuse", if I have to have one, at the driveshaft, which is easy.

The Dana 300 was never factory installed behind a cummins motor, however they are used all the time behind high horsepower applications. The Atlas transfer case was modeled after the Dana 300.
 
Seems like it would be a good part to have in chromoly, definitely a bad part to have cryoed seeing as it's already brittle. How hard to have it scanned and custom milled?
 
Seems like it would be a good part to have in chromoly, definitely a bad part to have cryoed seeing as it's already brittle. How hard to have it scanned and custom milled?

I don't know. It'd be prohibitively expensive though. What I will do is take some measurements of this AA unit so that I can look into it.
 
Got in touch with JB conversions. They said they've never heard of that shaft breaking before, but said there's no warranty and when asked about how much power they're supposed to be able to handle, their response was "everything has its limit". They have no shafts in stock and wont for 6 months or so.

Called Advance Adapters and they have 19 on the shelf. Ordered one up with 2 day air shipped for less total cost than the part's list price on their website!! This is a second time that Advance Adapters has saved my skin. I LOVE ADVANCE ADAPTERS!!

More updates on Friday.
 
Great news!
 
Agreed! The problem though is that the AA input and the JB Conversions inputs are different. The AA input is not machined to accomodate a seal in the clocking ring. I'm thinking that the seal in the transmission (transmission output seal) will be sufficient, but I guess time will tell. I've not been able to find anyone who has broken this input, so I have no idea what the differences will be.
 
When I looked up Dana 300 it showed the output shaft as the week link. It looked like an identical break that you had on the input shaft.
 
When I looked up Dana 300 it showed the output shaft as the week link. It looked like an identical break that you had on the input shaft.

Exactly, which is why I've upgraded the rear output shaft :D The weak link of the case *should* be the case itself after the shafts are upgraded.

is it possible to mix up the output and input shafts?

Nope.
 
The case is cast iron right? And I'd suggest you buddy up with a good machinist... I see many machining projects in your future :)
 
The case is cast iron right? And I'd suggest you buddy up with a good machinist... I see many machining projects in your future :)

Yup, the D300 case is cast steel.

I'll do you one better. When I build my shop I intend to buy a CNC lathe and a CNC mill, although finding a good machinist probably isn't a bad idea either :D
 

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