lol now come join the 4:10 club

 

Glad it's worked out for you. Did he send you the motive OEM grade gears b/c after I had trouble w/ one set he told me about them, but I thought it wouldn't make a difference vs the blue box motive's? I agree w/ the other guys about heat cycling it at least a few times and then it should be good. What are you taking the temps w/ an infrared gun or what?

 

Yeah IMO the 500 mile thing is a myth. No one goes easy on new stuff for a full 500 miles with new vehicle anyways. I ran mine on jack stands for a good 15 minutes monitored the temp then drove it for 15 and monitored. No spikes so **** is legit. Drove it semi easy for 100 miles then let her hang loose.

 

Dog, I'm not disparing your knowledge but I've been a machinist for more than forty years and I understand there is a certain surface work hardening process involve when a gear set is run together. However by no means is there anywhere near enough temperature generated in this gear set to affect the molecular alignment or hardness other then the surface polishing of being run together. These gear sets are tough and all heat treatment and annealing was completed during the manufacturing process. If they run in without excessive heat or noise they are good to go. When has a dealer ever said to a new car buyer, "make sure you heat cycle that new differenial"? Good luck....

 

Yes, I ran the truck 25 miles at highway speeds and took the temp using a infared gun. Coming from the shop I ran it about 5 miles city driving and stopped to take the temps and re-install my SC tune. Then drove another 25 miles at highway speed and stopped again to take temps. Than another 35 miles on back roads at varying speed to home where I took temps again. All was good and with no noise. Actually quieter than the original factory set which had a very slight whine at about 55 mph.

 

That part is in the manual where they say new car break in is 500 miles and to vary your mileage..yada..yada.. Def more of an old school thing, but...

I'm not saying your gonna have trouble, but from a racing fanatic standpoint...I have seen many gear sets crumble from heavy abuse from no break-in period from something as simple as flex which is what happens when your romping on it, plus it's just a good idea to make sure everything is properly done. Backlash and other things can change after a few hundred miles.
But, yeah, most of it is within the surface mating and yes I do agree that most of the treatment process is done before it goes in the retail box.

 

Sure in hell beats the 3:55 pegleg club! lol

 

Your truck must feel like a rocket now with that much of a change?

 

Pretty much like going from my 3.73's to 4.56's on 35's

 

Ratz!!! Virginia is too far for me to drive. Dagnabbit!! Sounds like you found a true craftsman.