Cryogenic treatment can be used to improve the hardness of certain grades of steel.  Many years ago it was used as the "magic bullet" to raise the hardness of steel that has a high nickel content, such as 9310 or 4820, so that the gears don't wear out prematurely.

We personally have mixed feelings about Cryogenic treatment and most places don't temper the hardness down to a more acceptable number. If a shop can't tell you what the hardness of the gears were prior to treatment, what they hardened up to and what they tempered them back down to then they are most likely doing your gears more harm than good. Also, if there is any gain in durability to be had from Cryogenic treatment it's going to be quite low, less than 8% when treating the factory gears.  On top of that, when you take into consideration the way that the gear teeth wind or unwind from this process it makes one question the validity of doing Cryogenic treatment to the factory gears in the first place. If you want to have us Cryogenically treat your gears we ship them to the most respected shop in the business and let them work their magic.

 © 2008 TRE