Cupping/Feathering & Recommend New Tires

[5speedsilverado]

Will running 285s on a 8" wide rim be too tight of a fit or bulge too much where the edges may not grab as well?

just mounted some 285/60 r17 on my 8" wide wheels yesterday, the fit well on the wheel and dont bulge much at all

[RS/SS 4.8]

Is that 8 mm in by the suspension points. If this is after repairs than that can cause several problems. General tolerance is 3/-3 mm or less. Its been a while since I have measured a frame.

[MrHorsepowerLSx]

You already have 30k+ miles on them and they are a 50-60k mile tire. You are more then half way past their life expectancy, and if you are now just noticing "tire wear", I wouldn't worry about it, I would recommend rotating them more often to keep them more " square". And the alignment specs you posted were from 2008, has the truck been re-aligned or checked for worn parts. You should be rotating your tires every 3-5k ...well every oil change, and most people drive 12-15k a year, so if you are rotating your tires once a year, there is going to be a considerable amount of tire "wear". And a quick way to check the hubs is to jack up the truck one side at a time just enough to get the front tire off the ground and stick a large pry bar under the tire,and pry against the ground and "lift up and down in rapid succession" this up and down movement should transfer any "free play" through the pry bar into your hand and it will signify worn hubs. If it is tight and you don't feel anything, write down the mileage of the truck when you checked the hubs and then check them again in the next 15k miles. I hope this helps you out

[5speedsilverado]

And a quick way to check the hubs is to jack up the truck one side at a time just enough to get the front tire off the ground and stick a large pry bar under the tire,and pry against the ground and "lift up and down in rapid succession" this up and down movement should transfer any "free play" through the pry bar into your hand and it will signify worn hubs. If it is tight and you don't feel anything, write down the mileage of the truck when you checked the hubs and then check them again in the next 15k miles. I hope this helps you out

lower ball joint is what you just described, hub is grab the top of the tire with one hand and the bottom with the other and push/pull opposite of each other