There are several options available for those that want to try to make their gears last longer in high power applications. We have thousands of transmissions out there and have played with all of the common treatments. This is what we found:
Gear Modification Work
This is done by removing the sharp edges on the gear. This makes sense as any sharp edge on a stressed part is an area that can concentrate that stress and cause a failure. What engineers call a ‘stress concentration’ some refer to this as a ‘stress riser’. A stress concentration can cause a crack and to remove that stress concentration will help prevent failure of your gear. The problem is in order to remove these stressed areas you have to remove material. Removing material from a hardened and treated gear is risky and we believe it does more harm than good. Here is a gear that was worked on by another trans shop:
The gear teeth look great! Nice and smooth with the stress concentrations removed. The problem is it broke and this kind of break is not common to gears that are untouched, so something changed when the gear was smoothed and modified. We believe that this kind of gear work is not uniform to the gear and will create more stress concentrations at the microscopic level. It looks great to the naked eye, but it’s actually worse than from the factory. So just not doing it is the best option.
WPC GEAR TREATMENT
WPC is a permanent surface treatment that reduces friction while strengthening the part. Its unique micro-dimple formation pattern greatly reduces friction and is unmatched by conventional methods of surface treatment. It is a proven process that has been utilized for many years in the racing and automotive industry and is complimented by utilizing our Micropolish treatment. WPC can strengthen parts in two ways. First it adds an extremely high level of compressive stress at, and near, the surface. The second, is that the WPC treatment creates a Nano - Crystalline structure at the surface of the metal. Both of these mean that metal fatigue and crack initiation are both noticeably reduced; thus strengthening the gears and shafts inside of the transmission.
We believe this is one of the the best things you can do to your gears. It is a gentle polish on the gears done by machine that will smooth and remove some stress concentrations uniformly. It also polishes the gears in the area they make contact with other parts, so you have less friction loss which means less heat, better fuel economy, and longer life. This will not make your gears stronger, but with less friction there is less stress so you might see longer life from a gear after going through this process. Whether it’s worth the cost to you though is your choice.
- Less inertia = Less friction = Less fuel consumed
- Reduction of friction of metal to metal contact parts = Less wear and contact fatigue
- Lower operating temperatures = Increased power output and efficiency
- Increased power density = options of larger engines or smaller transmissions
- Increased durability = Lower replacement costs and fewer failures
- Additional Benefits:
- Improved bending fatigue resistance
- Reduced lubrication maintenance
- Quieter operation
- Reduces rotational torque
- No metallurgical degradation
- No geometrical degradation
Picture below of polished gears: