All new gear sets require a break-in period to prevent damage from overheating. After driving the first 15 or 20 miles it is best to let the differential cool before proceeding. We recommend at least 500 miles before towing. We also recommend towing for very short distances (less than 15 miles) and letting the differential cool before continuing during the first 45 towing miles. This may seem unnecessary but we have seen many differentials damaged from being loaded before the gear set was broken in.
Changing the gear oil after the first 500 miles is also recommend. This will remove any metal particles or phosphorus coating that has come from the new gear set.