It goes crazy at high speeds. Also if you change the gears but not the shift points... don't forget about those.

 

Just don't forget. Take it easy on them until 500 mile mark. Then give em hell.

 

I did about 5 heat cycles on mine and then let loose on them. Just yesterday I changed my gear oil, and after doing it i would NOT recommend changing it (if using OEM AAM gears as I did - I've read these are also heat treated to 1500 degrees at the factory and do not require a break in period like aftermarket gears). The oil was clean clean clean with nothing in it. I never changed my stock rear end oil for nearly 150k with no problems, but I went ahead and did it just because everyone here says do it...

 

What kind of oil do i need to run in the rear end to break them in? after the break in period what oil should I use?

for anyone who uses HP Tuners, Once a truck is registerd with them can it be used on any hp tuners program? Dynospeed tuned my truck with HPtuners and one of my friends has a laptop with hptuners that works at the shop thats putting everything in tomarrow, can he change the shift points and stuff?

 

the guy who put in my gears/trutrac put in 80w90 and I replaced it with 75w90 remember all non-synthetic

 

Non synthetic. I used 80/85/90