2" ironman lift, 285/75r18 and tires are rubbing the chassis. What happened? (2 Viewers)

[bluejack]

Installed ironaman 2" nitro gas lift with diff drop and 285/75r18 BFGs on my 2003. Hard right turn and I get a significant rub on the chassis. I had a 2000 model 100 series that I put 285/75r16 with just the torsion bar cranked and never had a problem. What in the world is going on? What's the best way to fix it? Spacers? Havent heard great things about those? I figured I'd have 0 issue after the lift putting on a tire that works with stock set up

 

[Trapper50cal]

285/75R16 tires are 32.8 inches tall by 11.2" wide
285/75R18 tires are 34.8 inches tall by 11.2" wide

16's - 285/75R16 Tires - https://tiresize.com/tiresizes/285-75R16.htm
18's - 285/75R18 Tires - https://tiresize.com/tiresizes/285-75R18.htm

To get to these numbers just google the size and the words "in inches" and the Tire Size page will be one of the search results.

The first number is the width, the second number is the sidewall "profile" and it represents a proportion of the width
not a measurement in and of itself. So both tires have the same width and sidewall height but the hole is two inches
bigger in diameter, hence the different overall height.

 

[David310]

You put some meats on there. A 1.25” spacer will push the tire out enough to clear or wheels with +25mm offset. Have you done the pinch weld mod? Interested to know what you have done to fit ~35” tires and how it rides.

 

[hoser]

285/75R16= 33" diameter
285/75R17= 34"
285/75R18= 35"
285/75R19= 36"

See the pattern?...

You'll probably need further pinch weld mods to fit...

 

[bluejack]

Ah! Clearly I'm the dumb ass here. Lesson learned!

I have been on here long enough to get the joke about whats the biggest tire I can put on without a lift and was hard wired to say 285. My 2000 100 series had 285/75r16 with no lift. and I was sure since the rims looked identical that my 2003 had the same diameter. When I got the new tires I told the guy 285s and thats what I got. But I should have known better. Back to the old tires that luckily I still have. Anyone want some 35"s?

 

[GTV]

I’ve been wondering where the limit was for frame rub, thanks for clearing that up.

285/70’s will be a lot easier to fit.

 

[David310]

Ah! Clearly I'm the dumb ass here. Lesson learned!

I have been on here long enough to get the joke about whats the biggest tire I can put on without a lift and was hard wired to say 285. My 2000 100 series had 285/75r16 with no lift. and I was sure since the rims looked identical that my 2003 had the same diameter. When I got the new tires I told the guy 285s and thats what I got. But I should have known better. Back to the old tires that luckily I still have. Anyone want some 35"s?

I’ll take them!!

 

[bluejack]

Currently either going to put my 275/65 18s back on which kinda look like pizza cutters with the lift or my tire guy thinks he might be able to swap the 285s for a new set of 33" diameter tires. I wonder if 285/70r18 will avoid the rub. Then there are the 33x12.50 but with the increases width I will probably get rubbing there too. I don't really want spacers and I don't want to do the pinch weld mod. Just want to fill the fender wells for esthetics really.

 

[David310]

if your tire guy can swap for 33s, I would do it. That’s about as big without having to do supporting mods. 275/70/18 is the popular size.

You can keep the 35s if you push the tire out (space or new wheel), pinch weld mod, relocate windshield washer fluid, heat gun the fender liner, and cut a bit off the ends of the front bumper. This will work for pavement/fire road use.

 

[Trapper50cal]

Wish I could take them off your hands...I have the opposite scenario...all the lift you can do without body spacers or a SAS but running 255/85r16's with spacers. Alas, can't drop coin on tires when the ones I have are in such new shape.

 

[GTV]

Currently either going to put my 275/65 18s back on which kinda look like pizza cutters with the lift or my tire guy thinks he might be able to swap the 285s for a new set of 33" diameter tires. I wonder if 285/70r18 will avoid the rub. Then there are the 33x12.50 but with the increases width I will probably get rubbing there too. I don't really want spacers and I don't want to do the pinch weld mod. Just want to fill the fender wells for esthetics really.

275/70’s are your best option.

 

[jaewastooshort]

Wish I could take them off your hands...I have the opposite scenario...all the lift you can do without body spacers or a SAS but running 255/85r16's with spacers. Alas, can't drop coin on tires when the ones I have are in such new shape.

Don't know if you're ever down in SE texas, but once my FN 17's come in I'll be pulling off my 285/75r16's and don't really expect to be going back to the stockers. I think I've only got about 10k-15k miles on them.

 

[Trapper50cal]

Don't know if you're ever down in SE texas, but once my FN 17's come in I'll be pulling off my 285/75r16's and don't really expect to be going back to the stockers. I think I've only got about 10k-15k miles on them.

Appreciate that! I'm trying to get into something approaching a 34" at least. And these 255/85R16's I have on are just sub 33's already. But that's a kind offer. If I stay with 16's (rather than getting 18" OEM steelies) I'll be actively seeking 295/75R16's which are 33.4 x 11.6.

 

[bluejack]

Tire guy said I can swap out the 285s for a set of 275/70r18s and actually get a bit of a $$ back. Thanks for the responses. Honestly, I'm happy to be going back down in size. The 35's certainly made the truck look great along with the lift but I felt they really affected handling and braking times negatively.