Moser noise too
It wasn't a few passes, it was one pass. By not set up right, do you mean pinion depth wrong? In which direction?
I took the 12 bolt apart today. I have 4.10 Motive gears in it. I measured the backlash at .009, which is on the tight end of the spec (.008 - .012). The contact patch is larger than I have ever seen with OEM gears, and is biased a bit toward the heel, but not obviously way off. I can't check pinion depth as I don't have the tool, but I did verify that there is no endplay in the pinion. Long story short, I still don't know what prompted the sudden onset of howling on decel, but since everything looks OK, I will ignore it.
I switched to Richmonds, and now after 2 years, quiet as a mute.....
I would shallow up the pinion depth as earlier stated....


