My trailer tires have uneven wear, feathering on the inside of the left tire and outside of the right tire. While verifying the axle alignment I noticed the swing tongue has play in it, about 3/8 to 1/2" up-down at the ball mount and a bit side to side. Uh Oh... I looked closely at the pin holes for the swing tongue and there is a bit of wear in the holes, enough to allow the swing tongue to move around a bit.
I continued the alignment check by clamping a C clamp into the center of the ball mount (put it where the ball goes) and measured to the leading edge of the bearing buddy, both sides were exactly 189", and 188 15/16" if I pulled the tape hard. I didn't check (but need to) see how the alignment looks if I kick the tongue from side to side. But, even is the tongue is pulling off center by 1/4", I don't think this is going to cause the alignment to be off a significant amount, 1/4" at the wheel yes, but not 1/4" from side-side at the tongue. I wouldn't think.
So besides the axle alignment being off, is there anything else that will cause the tires to wear odd like this, feathered on the left tire's inside and right tire's outside?
I should add, this trailer/tires are fairly new to me as I have only pulled it a couple times. The tires look to be wearing fine besides the feathering, just dry rotted from age and flat spots from sitting for a long time.