That's a defect. It MAY have been there since you got them.
I haven't had a set do that, but I've seen other tires with it...and while not that unusual in the tire world, its still not normal.

_________________________
- TJ
2001 Xterra '03 VG33, SE 5 spd, 305/70/16's, Revolvers, UBSkidderz, Doubled AAL's, 3"SL/2"BL, winch/bumpers, skids, sliders, OBA, Snorkel, pine stripes....
Friends don't let friends drive stock.
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