After a gear set is manufactured, proper set up and break in is crucial. Even after perfect set up (backlash, bearing preload, etc.), the ring and pinion still need time to "break in" and mesh their pattern into each other. After initial install, the gear set will run much hotter than normal. If you get the gears too hot before the break in period is over, (i.e., driving for an extended period of time without a cooldown, burnouts/racing/off-roading, towing, etc.), you will do irreversible damage and burn your gear set up. Please follow the below procedure after initial install:

1.) After checking proper fluid levels, drive your vehicle under normal operating conditions in stop and go traffic (i.e., main or side streets only, no highway driving yet). No racing, no off-roading, no burnouts, no hard starts, and no towing!

2.) Drive your vehicle for 15-20 minutes and park it.

3.) Let the axle assembly completely cool down. This could take upwards of 3-4 hours.

4.) Repeat the 15-20 minute drive and cool-down period at least two more times!

5.) Now it's time to take it on the highway. Take your vehicle for a 15-20 minute drive. You'll want to vary your speed between 50mph-70mph, not keeping it at the same speed for long. Park it and let the axle assembly completely cool.

6.) Repeat your highway drive and cool-down period at least two more times!

7.) Drive the vehicle normally for at least 500 miles mixing in street and highway miles. Do not take your vehicle on road trips in the first 500 miles.

8.) After 500-1000 miles on your new gear set, you'll need to change the oil. Check for excessive metal in the oil or any signs of gear damage.

9.) Break in complete!

10.) Note: If your vehicle is used for towing, repeat the break in procedure the first time it is used to tow!