This was posted by Proformance back in may 2012. I have no idea if or what has changed since then:
Quote:
Originally Posted by rockyota83 View Post
what brand d60 gears are you running? ratio? have you broken any gear sets yet?
"We broke some ring and pinions from a USA manufacturer, before we discovered that most (We have not found any yet) USA made ring gears (Other than the 10" TT Gears) are made in Korea or China.
We did some metal testing and discovered that the gears were 62-65 rockwell on the outside and the hardness dropped instantly to 25-22 Rockwell less than 1mm below the outer surface - absolute junk. I then rang EVERY diff gear supplier in the USA that I could find and they all admitted (After I asked the question many many times) that their diff gears are not made in the USA and they are actually made in China/Korea.
I offered to purchase 3 sets from each of the most known USA diff gear "manufacturer" (Two for the truck for testing and one to cut open and test the material and heat treatment and perform a full metal analysis to see what material they are made from) but all sugested that their gears are only suitable for road use (Really Really hard for long life, but not for competition).
We now source our ring gears from DANA direct - simple.
When we have finished development of our new portal hubs, the diff gears will only experience 50% of the load, and we will have a super stong drivetrain.
Thanks for the question"