So I'm finally going to bet around to installing my 09 Getrag diff in a couple of weeks. I was wondering what you guys are doing for break-in and what gear oil are you using. I talked to my local gear/axle shop and the owner said to run dino oil in a high performance car. He said that the synthetic can't handle the pressure like a dino oil. He also recommended to go with 70-140 weight oil instead of the 70-90. After a little more research, I found the following. It appears that the following is for an ENTIRE NEW clutched differential. Upon differential installation, and fluid top off, proceed to drive vehicle to a controlled area where several circles/figure eights can be performed. Drive vehicle (at idle speed) in 20 figure eights, full lock to full lock. Then drive (at idle speed) in 20 full lock circles left, 20 full lock circles right. All Diffsonline differentials (excluding Kaaz LSDs) require a 1200 mile break in period. Do not exceed speeds of 85mph as bearings may overheat. Drive vehicle moderately without extreme load differences such as shocking (hard shifting with swift clutch use). After 1200 miles, change oil in differential with recommended fluids. Then the procedure below this is for when installing new gears on a used differential. Use only high quality name brand gear oil and fill the differential until the oil spills out the plug hole. Positraction carriers require anti-friction additive. All new gear sets require a break-in period to prevent damage from overheating. After driving the first 15 or 20 miles you must let the differential cool for 30-40 minutes before proceeding. Drive 500 easy miles before towing. Tow for very short distances (less than 15 miles) and let the differential cool before continuing during the first 45 towing miles. Change the gear oil after the first 500 miles. This will remove any metal particles or phosphorus coating that has come from the new gear set. Any thoughts or opinions?
