Wondering if you guys can figure this one out. So last week I had 3.73 gears, all new bearings and bushings, and new Moser axles installed with Royal Purple diff fluid. I picked the car up and when I took a turn I could hear the posi unit popping, sounded like something was binding?? Took it back to the shop and the guy said maybe it was the Royal Purple......I'm like WTF, lots of people use RP. So I changed the fluid Friday and I just put Valvoline back in with friction modifier.....and now the car is fine, no binding?? Doesn't make any sense.