New tires wearing uneven?

[smdk2500]

I believe the sticker says 50 front and 80 rear but i never haul anything so i just put the same front and rear also this is kinda off topic but i went from a 245/75r16 to and 265/75 and i have 4.10 gears and the speedo is not off at all am i missing something? I thought if i went up in size it would at least throw it off a little bit

I did the same tire size changes on both of my 95 and they both have the same gear ratios as you do and mine still reads about the same with the same tire sizes. Ive checked both with a gps speed app on my phone in both trucks.

 

[White96k2500]

I did the same tire size changes on both of my 95 and they both have the same gear ratios as you do and mine still reads about the same with the same tire sizes. Ive checked both with a gps speed app on my phone in both trucks.

I just couldn’t believe it I figured it would throw it off by 5mph

 

[Hipster]

The alignment guy should have given you a printout with caster, camber, toe, SAI, turn radius, set back, and thrust angle. Caster, camber, and toe measurements only tell part of the story and can be within spec and there can still be issues with tire wear. A common cheat is to delete the other numbers from the printout. If the turn radius is off from a tweaked knuckle the caster, camber, and toe can be set "with-in spec" straight ahead on a rack but it will scrub tires in turns or long sweepers. Not only do the number need to be within spec but they need to be very close side to side. Just an example, if the spec is -1 to +1 dregrees it can be off 2 degrees side to side and both sides are green on the printout but it's off.

What's the numbers? Take a pic of the sheet and post it.

 

[stutaeng]

I just couldn’t believe it I figured it would throw it off by 5mph

Yeah, not that much difference. You can check here: https://tiresize.com/speedometer-calibration/
2.5 MPH at 65 according to this calculator. I don't even know if the speedometer is that accurate to begin with, lol.

It is a linear relationship, meaning 5 mph off at 80 MPH is only 2.5 MPH at 40 MPH, for example. Does that make sense? The LT tires need more pressure than P-series for heavy loads. I think my K3500 SRW calls for something like 50/60 psi or 50/80 psi. I also have LT 265/75/R16s on mine.

 

[White96k2500]

The alignment guy should have given you a printout with caster, camber, toe, SAI, turn radius, set back, and thrust angle. Caster, camber, and toe measurements only tell part of the story and can be within spec and there can still be issues with tire wear. A common cheat is to delete the other numbers from the printout. If the turn radius is off from a tweaked knuckle the caster, camber, and toe can be set "with-in spec" straight ahead on a rack but it will scrub tires in turns or long sweepers. Not only do the number need to be within spec but they need to be very close side to side. Just an example, if the spec is -1 to +1 dregrees it can be off 2 degrees side to side and both sides are green on the printout but it's off.

What's the numbers? Take a pic of the sheet and post it.

The guy never gave me a paper, the only thing i got from him was a recipe

 

[HotWheelsBurban]

On my old R2500 square Burb, it had 245/16 LT 10 ply radials, B F Goodrich commercial T/A's( no white letters and much cheaper but just as good of a tire),and I ran 80psi in them. By comparison, even the 30/9.5 -15 michelins we ran on the first 99 Burb ( that's what was on it when purchased used, on the factory 10 spoke alloys) ran at 45 IIRC. The 235 coopers on my current truck run at 36 unless I'm traveling fully loaded, then 38 in the front and 40 in the back. The LT truck tires have more plies and a stiffer sidewall so they run at a higher pressure.

 

[HotWheelsBurban]

The guy never gave me a paper, the only thing i got from him was a recipe

Don't feel bad, a good alignment shop is hard to find!

 

[White96k2500]

Don't feel bad, a good alignment shop is hard to find!

He is supposed to be the best around here but I wasn’t really impressed. On the paper he gave me it said he was supposed to center the steering wheel and tighten the gear box if needed but he didn’t and the steering is pretty loose it’s not really a big deal I can do it myself just wish they did everything they were supposed to

 

[HotWheelsBurban]

He is supposed to be the best around here but I wasn’t really impressed. On the paper he gave me it said he was supposed to center the steering wheel and tighten the gear box if needed but he didn’t and the steering is pretty loose it’s not really a big deal I can do it myself just wish they did everything they were supposed to

Yes that's the least you'd expect when you're paying someone to do some work for you!