At least we know were beau's bad luck went...

 

 

break-in period my ***, shitty work imo, ill never go there for sure

 

From Randy's Ring and pinion website.

What is the break-in proceedure for a new set of gears?
All new gear sets require a break-in period to prevent damage from overheating. After driving the first 15 or 20 miles it is best to let the differential cool before proceeding. I recommend at least 500 miles before towing. I also recommend towing for very short distances (less than 15 miles) and letting the differential cool before continuing during the first 45 towing miles. This may seem unnecessary but I have seen many differentials damaged from being loaded before the gear set was broken in.
I also recommend changing the gear oil after the first 500 miles. This will remove any metal particles or phosphorus coating that has come from the new gear set

 

I don't know any details on the first installation, except for the fact that the pinion shim was correct.

The second one was text book like said.

 

I would trust Bryan before the guy that was doing burnouts with a brand new gear set

 

Yes, Sam did a burnout right out of the shop, but that could not have produced sufficient HEAT to soften the gear metal and cause them to step.

However, I do not know how Yukon hardens their gears. I am trying to get to the bottom of this as we speak. Today I read the Failure Analysis section of a a gear manual from a Turbomachinery Symposium, and it mentioned that gears will deform (step) if the are not of sufficient hardness, and subject to heavy loading.

With that said, IF Yukon says to use the 500 mile rule because by that mark, the gears will have been work-hardened to the proper hardness, then it is possible that the first set of gears were damaged when Sam did the burnout because they were overloaded before the proper hardness could be achieved through the break-in, not because the gears got hot.

I will call Yukon about this and find out for sure.

FYI, Mark warrantees his installs, and Randys is supposed to warranty the gears.

 

 

That is how it supposed to work. I don't warranty parts unless the failure is caused by something I did. If the part fails due to a manufacturing defect, there is nothing I can do.

RR&P is supposed to warranty their gears because they are a product manufactured by RR&P. Like said, I am looking into it, and I WILL get some answers.

 

"supposed to"