Gear break-in is indeed an important process to ensure the longevity and performance of gears. The controlled heat cycling and seasoning of the gear's contact surfaces during break-in help harden the gears and prevent damage or failure. Following the proper break-in procedure can make a significant difference in the durability and performance of the gears.
The first drive after installing the gears should be at in-town speeds, around 15 to 20 mph. It is recommended to drive for approximately 20 minutes and then allow the differential to cool off for about half an hour. Repeat this process a few times. Afterward, you can proceed to do some freeway runs, driving around 15 miles and then pulling over to let the drivetrain cool down for about 20 minutes. Repeat this cycle for a total of approximately 45 miles. Although it may seem tedious, this process helps ensure the gears are properly broken in, preventing damage and excessive wear.
Proper lubrication is also crucial during the break-in period. For the first 500 miles, it is recommended to use 80W-90 conventional oil. After this initial period, the oil should be drained and replaced. If your gear setup features a Dura Grip clutch-type limited slip differential, it is advisable to use a non-synthetic oil. However, if you have a helical LSD or a locker, synthetic oils are suitable for those applications.
If your vehicle is used for towing or extreme off-roading, additional pressure is applied to the gears, particularly the pinion. This pressure can slightly shift the pinion's position on the ring gear teeth, necessitating further hardening of the gears in that area. It is highly recommended to follow the same break-in procedure while towing, hauling, or driving off-road, even if you have already completed the initial break-in process. Repeat the in-town and freeway drives at the specified speeds and distances.
Long-distance hauling can generate excessive heat without adequate cooling, which can lead to gear oil breakdown and damage to the gear surfaces. Therefore, it is advisable to change the gear oil after the first 500 miles to maintain optimal performance and protect the gear set.
By following these guidelines for gear break-in, you can protect your investment and ensure the best performance and longevity of your gears.
