Question - Leveling and Front Wheel Geometry

[Joseph Garcia]

Hi Folks,

I'm doing some pre-work research on potential wider tire options for my 2007 Yukon XL Denali, say possibly 285, 295 or 305, and reading through existing threads, it appears that I will need to do some leveling/lifting, in order to accomplish this. I have also read that the maximum recommended front level/lift for this vehicle is 2-2.5 inches, in order to keep the CV joints from wearing out prematurely.

I am currently running 275/60x20 tires (stock size is 275/55/20), and I have no rubbing issues. Also from reading the threads, it appears that I will be limited to the existing overall tire diameter of 33 inches for any potential wider tire options, without having to consider full lift kits for higher lifts, which I am not interested in pursuing at this time.

Before moving any further forward on this project, I'd like to understand if the stock front wheel geometry (caster, camber, toe-in) will change as a result of leveling up to 2.5 inches, and if it does, can the leveled front wheel be adjusted back to stock geometry. If the leveled front wheel cannot be adjusted back to stock geometry, I would imagine that the tires would wear unevenly, thus reducing the life of the tires.

I'm trying to keep my eyes wide open, before committing to this project, so that I do not get blindsided by unexpected up-front or recurring costs (I know, good luck on that!), so any thoughts on my leveled front wheel geometry question will be much appreciated.

 

[Big Mama]

what’s the aspect ratio of the tire? 285/60, 295/50 305/45? Unless you’re going big or have a deep offset wheel you don’t need to raise the front unless that’s the look you’re after.

 

[Joseph Garcia]

Thank you for your quick reply Big. Much appreciated.

If I do not need to raise the truck to move to a wider tire, that would be my preference at this time, and then the front wheel geometry question becomes a moot point. Also, while I am open to some very minor plastic trimming, or minor plastic wheel-well liner adjustments/tie-backs, I do not want to do any metal cutting or bending to move to a wider tire.

I plan to use the existing stock GMC 20" wheel, 8.5Jx20 ET31, which I believe translates to a positive 31mm offset.

I plan to consider an aspect ratio for each potential tire width, which are the ones that you mentioned, such that the overall time diameter does not exceed 33 inches (the overall tire diameter of my existing 275/60x20 tire size). However, I believe that at some width/aspect ratio combination, the width itself will become a limiting factor, in not allowing the tire to turn fully in each direction, without rubbing, but I do not currently know where that break point is. So.....

• 285/55x20 has an approximate 32.4 inch overall tire diameter, and appears to be the largest that I can use at this width. 285/60x20 has an approximate 33.5 inch overall tire diameter, which may be too large.
• 295/55x20 has an approximate 33.1 inch overall tire diameter, and appears to be the largest that I can use at this width. 295/60x20 has an approximate 34.1 inch overall tire diameter, which may be too large.
• 305/50x20 has an approximate 32 inch overall tire diameter, and appears to be the largest that I can use at this width. 305/55x20 has an approximate 33.2 inch overall tire diameter, which is close to 33 inches, and may fit.

Thoughts?

 

[Big Mama]

I’m not sure a 305 will fit well on that wheel but I may be off a little. I have 305 now on 22” wheels and lowered the only modifications I did was pulling the inner fender back in a few places with zip ties. You’ll notice lots of these on the road not lowered with little mods the right front is usually the culprit if at all. If you know your tire guy well he’ll know for sure. The other thing to consider is ride quality the shorter sidewall rides a little rougher

 

[Joseph Garcia]

Thank you Big. Again, much appreciated.

One of the tires that I am considering is the Michelin Defender LTX M/S, not a gnarly tire, but a long lasting highway all season tire. I contacted Michelin about the 305 width fitting on an 8.5" width rim, and though it is the minimum recommended width wheel for that tire width, they told me that it would fit OK.

Good point on the stiffer ride with the lower sidewall, but that is OK, as I've always stiffened the suspension on all of the cars that I've owned.

It looks like it is now time for me to check it out with a real tire, and then adjust as needed.

Thanks again!

 

[HiHoeSilver]

Thank you Big. Again, much appreciated.

One of the tires that I am considering is the Michelin Defender LTX M/S, not a gnarly tire, but a long lasting highway all season tire. I contacted Michelin about the 305 width fitting on an 8.5" width rim, and though it is the minimum recommended width wheel for that tire width, they told me that it would fit OK.

Good point on the stiffer ride with the lower sidewall, but that is OK, as I've always stiffened the suspension on all of the cars that I've owned.

It looks like it is now time for me to check it out with a real tire, and then adjust as needed.

Thanks again!

That's a very popular tire choice on here, and by all accounts, a great one.

 

[Joseph Garcia]

Thanks HiHoe.

Good to know that others have already validated the tire brand/model that I am considering for my truck.

 

[jwth]

Hi Folks,

I'm doing some pre-work research on potential wider tire options for my 2007 Yukon XL Denali, say possibly 285, 295 or 305, and reading through existing threads, it appears that I will need to do some leveling/lifting, in order to accomplish this. I have also read that the maximum recommended front level/lift for this vehicle is 2-2.5 inches, in order to keep the CV joints from wearing out prematurely.

I am currently running 275/60x20 tires (stock size is 275/55/20), and I have no rubbing issues. Also from reading the threads, it appears that I will be limited to the existing overall tire diameter of 33 inches for any potential wider tire options, without having to consider full lift kits for higher lifts, which I am not interested in pursuing at this time.

Before moving any further forward on this project, I'd like to understand if the stock front wheel geometry (caster, camber, toe-in) will change as a result of leveling up to 2.5 inches, and if it does, can the leveled front wheel be adjusted back to stock geometry. If the leveled front wheel cannot be adjusted back to stock geometry, I would imagine that the tires would wear unevenly, thus reducing the life of the tires.

I'm trying to keep my eyes wide open, before committing to this project, so that I do not get blindsided by unexpected up-front or recurring costs (I know, good luck on that!), so any thoughts on my leveled front wheel geometry question will be much appreciated.

Caster, camber and toe adjustments are there for any tweek's needed at the assembley line due to variations of the steering geometry in assembley, slight differences in part manufacturing.
The rear differential and banjo hold dimensions due to rigidity of the construction but not so with the flexible front steering assembley.
Raise the front end ant the camber changes as well as the toe in/out.
If there is enough movement left in the adjustments it can be reset, if it is to far out it does take some rework.

 

[Joseph Garcia]

Thank you, JW, for your insight. Much appreciated.