[ccl]

Just inspected the tires and noticed that all 4 tires are worn down pretty bad on the inside, 1 of the tires is showing the threads.
the rest of the tire looks in great shape.
the tires are 3 years old and have about 30,000 miles

The tires are Bfg commercial t/a lt235/85r16

Any thought on why they are wearing so bad on the inside, i checked the springs and axle and everything seems ok.
I also replaced all the brakes nd didn't see any sign of them locking up.