Input shaft tore up, custy blames moly...?

[pileoford]

Got a custy that has a 98 Dodge with(of course) the Cummins T/D. NV 4500. Tore two adjacent teeth clean off the input shaft. Blames me for moly coating the tranny. I know that colloidal moly can handle psi's in excesss of 500,000. Can anyone get me the failex load test specs for gear oil, v. moly/gear oil. This guy is a dolt, but if confronted with facts, he may be manageable. I am going to charge him regardless, but I live in an isolated town, and it could hurt me if he runs his mouth and spews ignorance all over.
I have googled it, and apparently the specs are quite obscure.

 

[Metalguy]

If you can take a good, closeup photo of one of the fracture surfaces, we may be able to see if it's a ductile -gross overload fracture of a more-likely fatigue fracture. Fatigue involves a relatively slow growing crack.

 

[patdaly]

pileoford, is this a 24V 98.5 or a 12V? Any 6BT can kill the stoutest NV4500 without breaking a sweat, if it has been turned up. Though I have no documentation to provide, I run Moly in the rear of my Nova to keep the thing from shucking the 9" gears. ( prior to moly treatment I could kill one fast )
As Metalguy said, if you can provide a good picture of the failure we could probably help. My bet is on a gross overload, knowing the source of the torque.

 

[pileoford]

Thanks Guys,
I do not have the shaft here, as this guy went and had someone else fix it, apparently having convinced himself that I am incompetant. The good news is that I have located it, and will have it shipped back here, so photos will be forthcoming. As this one may well end up in court, I will be extremely interested in your diagnosis/ examination.
If need be, is there one of us who is affiliated with a lab that does forensic exams where I can get an admissable report?
Thanks again, chris

 

[pileoford]

Oh, BTW, it is a 24v that has been turned up.
chris

 

[Metalguy]

I'm not affiliated with this lab., but have used them for many years.

Try METL in Phoenix.

 

[patdaly]

I have used Sherry Labs in Muncie Indiana for years. We are not a large user though...... Good luck and I would take the position that there is no way for you to sufficiently upgrade the NV4500 to resist the turned up 6BT. Torque ratings are designed in, and there is a reason they switched to the NV5600.

 

[icrman]

If it goes to court. Here's my suggestion.
Of course he could change the engine ratings ahead of time.
It needs to be dynoed. And the gear material checked for hardness. Manufactures max input torque specs. And also run the info here so some of us can calculate the loadings.
I suppose he's drag racing it. So he's applying full torque instantaniously.

 

[pileoford]

All I know is what the guy has told me, and that is that it is turned up about 60 hp. No idea what the torque/gear ratio is, but will attempt to find out. This guy took off for a test drive, before paying, and never came back.
I'll prolly have to sue him now. The good news- I have the gear back, and will get you the photos. Probably tomorrow.
I have no way of knowing how the previous owner used it, but this guy has a 12 horse trailer, and raises quarter horses. And, he has a rotten temper.
I suspect, in a childish fit, (to which he is given,) he popped the clutch HARD, and instantaneously sheered the teeth.
I'll share all relevant specs/ facts as I gather them.
This could prove interesting.