AT4 with Rough Country 2" Leveling Kit and 35" Toyo Tires

[rikhek]

I wanted to share the fitment of a Rough Country 2" AT4 specific leveling kit and 35" tires on OEM 18" wheels with the forum.  After installing the AT4 specific RC leveling kit I was able to fit 285/75/18 Toyo Open Country A/T III tires without any rubbing.  The tires are advertised as being 34.8" tall and 11.3" wide.  I don't have any rubbing at full lock but it's pretty close.  I think if I was at max articulation and full to nearly full lock in an off road setting I'd rub the fender liner a bit.  Not enough to do anything about it but it would just rub.  In over 1,000 miles of daily driving I've not rubbed a single time.

 

Noteworthy comment/observations:

 

1.  If I went with a 35" x 12.5" I would have significant rubbing with the fender liner.  A true 12.5" wide 35" would not have adequate clearance.  This is one of the reasons I went with the "narrow" 11.3" wide Toyo's.

 

2.  Make sure you get an alignment after installing a leveling kit.  My truck was significantly toed-out, outside the acceptable range with the leveling kit and resulted in a "darty" ride with a "floaty" feel.  After getting an alignment and some toe-in the truck drives much better.

 

 

Edited September 16, 2020 by rikhek

[Rgpie75]

That looks great. Hoping to go with something very similar on my AT4 soon.


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[Gangly]

Looks Good! 

I'm curious about your UCA angles being different with a different tire size.  Tire size should have zero affect on your UCA angles.

[J2Jones]

2 minutes ago, Gangly said:

Looks Good! 

I'm curious about your UCA angles being different with a different tire size.  Tire size should have zero affect on your UCA angles.

I was actually about to ask the same thing.  Having a hard time visualizing how tire size would impact UCA angles.

 

[rikhek]

1 hour ago, Gangly said:

Looks Good! 

I'm curious about your UCA angles being different with a different tire size.  Tire size should have zero affect on your UCA angles.

Yeah, you're correct.  I didn't think that through but different tire size won't change UCA angle.  My comment was based upon just a visual observation.  With the truck up higher I think it just gives an optical illusion of the angle being less severe.  Changing the center line of the spindle/axle up or down doesn't change the control arm angles.

 

Sort of funny as looking at it right now it still looks like a less severe UCA angle even though I know it's unchanged.

 

Sorry, my bad for posting without thinking it through and just going upon what I thought my eyes were telling me.  I've corrected my original post....

Edited September 16, 2020 by rikhek

[Dani2005]

Finally, someone with the factory 18s (not the 20s) and putting more rubber on the rims.

Thanks for posting!

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[rikhek]

Yeah, my philosophy with 4 wheel drive vehicles that are actually used off road is to fit the smallest "wheels" that will clear the calipers along with tires with the tallest sidewall.  I personally don't understand putting large wheels with low profile "rubber band" tires on a 4 wheel drive vehicle.  It defeats the purpose.

 

Note I emphasized smallest "wheels" to make the point that they're not RIMS, they are wheels.  One of my pet peeves is when folks call wheels "rims".  A rim is just one component of a wheel.  I know most find this to be petty but I just can't help myself.  Calling a rim a wheel is like calling a cylinder head an engine... 

Edited September 16, 2020 by rikhek

[Dani2005]

2 hours ago, rikhek said:

Yeah, my philosophy with 4 wheel drive vehicles that are actually used off road is to fit the smallest "wheels" that will clear the calipers along with tires with the tallest sidewall.  I personally don't understand putting large wheels with low profile "rubber band" tires on a 4 wheel drive vehicle.  It defeats the purpose.

 

Note I emphasized smallest "wheels" to make the point that they're not RIMS, they are wheels.  One of my pet peeves is when folks call wheels "rims".  A rim is just one component of a wheel.  I know most find this to be petty but I just can't help myself.  Calling a rim a wheel is like calling a cylinder head an engine... 

What I really want to see is someone able to get 17s with 35" tire as that's my goal. I know level is probably needed, but just wanna see the look on the GMCs.

[Gangly]

27 minutes ago, Dani2005 said:

What I really want to see is someone able to get 17s with 35" tire as that's my goal. I know level is probably needed, but just wanna see the look on the GMCs.

Your gonna be waiting awhile for somebody to downgrade their braking system to fit a smaller rotor and caliper setup

 

I agree though, I have 20's on my truck and I constantly find myself searching craigslist for TrailBoss 18's.  I prefer more sidewall for off-road, less sidewall for on-road.

[Dani2005]

4 minutes ago, Gangly said:

Your gonna be waiting awhile for somebody to downgrade their braking system to fit a smaller rotor and caliper setup

 

 

I agree though, I have 20's on my truck and I constantly find myself searching craigslist for TrailBoss 18's.  I prefer more sidewall for off-road, less sidewall for on-road.

I think it's just finding the right 17 or adding a small spacer if needed. There are YouTube videos of 17s fitting and clearing the calipers. Just have to really grind the numbers to see which will clear. 

[Matt Woodard]

@rikhek - any other pictures from front/rear with that level and tire setup? 

I was thinking of going with the Zone Offroad 1.75 kit.  (https://zoneoffroad.com/products/175-in-leveling-kit-2019-2020-chevy-silverado-trail-boss-gmc-sierra-at4?variant=33477556338776)  They claim to have maintained factory steering geometry and specifically not affecting the ball joints / UCAs by putting them in a severe bind by changing the angles too drastically.

[Matt Woodard]

Also @rikhek - I was going to go with the Ridge Grappler in a 285/70r18.  Smaller tire (34") but little wider at 11.5".  Curious how much clearance you have between tire sidewall and stock UCA with those 285/75s?  Extra 1/4" width on my tire means (theoretically) I would have 1/8" less clearance from sidewall to UCA on my anticipated setup of 285/70s.  Thanks man.

[Supercup]

Here is a photo of my 2019 AT4 Carbon Pro - with Ready Lift 2" level and UCA's - with stock 275/65/18 dura trac - then a photo of my 2020 AT4 Carbon Pro (traded for tow mirrors and camera tech for trailer) with BDS 2.5" lift kit.  You will note pretty extreme angles for the 2" level - but dead level axel for the BDS lift - with diff drop bracket as part of kit.

 

Level's on AT4 and Trail Boss are going to max your CV angles - it works - but may not be the best outcome long term.   For the cost and look, it is the way to go.  But if you can afford the True, BDS, RC "lift kits" that give you 2.5" lift and drop your diff - you will have best of both worlds - it is more cost - but if you don't go with coilover shocks the cost difference is about double a level kit. 

 

2019 AT4 with Ready Lift SST 2" level kit

 

2020 AT4 wtih BDS 2.5" lift kit 

[doggfatherone]

On 11/23/2020 at 6:37 PM, Supercup said:

Here is a photo of my 2019 AT4 Carbon Pro - with Ready Lift 2" level and UCA's - with stock 275/65/18 dura trac - then a photo of my 2020 AT4 Carbon Pro (traded for tow mirrors and camera tech for trailer) with BDS 2.5" lift kit.  You will note pretty extreme angles for the 2" level - but dead level axel for the BDS lift - with diff drop bracket as part of kit.

 

Level's on AT4 and Trail Boss are going to max your CV angles - it works - but may not be the best outcome long term.   For the cost and look, it is the way to go.  But if you can afford the True, BDS, RC "lift kits" that give you 2.5" lift and drop your diff - you will have best of both worlds - it is more cost - but if you don't go with coilover shocks the cost difference is about double a level kit. 

 

2019 AT4 with Ready Lift SST 2" level kit

 

2020 AT4 wtih BDS 2.5" lift kit 

Thanks for the pics. I have a 2021 1500 AT4 and just had the SST 2 inch kit installed. I love the look of the kit and rides ok. I say ok because the ride isn't as smooth as before. More bumpier than before the kit. Everything else is OEM and I'm wondering if it is worth the 2 inches now. I plan to put Nitto 33's with 22x10 (-18) 4 Play wheels on it and need it to fit the 33's. Just seeing who else have had the same issue.

[Smrtasp]

On 5/23/2021 at 5:30 PM, doggfatherone said:

Thanks for the pics. I have a 2021 1500 AT4 and just had the SST 2 inch kit installed. I love the look of the kit and rides ok. I say ok because the ride isn't as smooth as before. More bumpier than before the kit. Everything else is OEM and I'm wondering if it is worth the 2 inches now. I plan to put Nitto 33's with 22x10 (-18) 4 Play wheels on it and need it to fit the 33's. Just seeing who else have had the same issue.

You did the same that I did to my 2019 Denali. It never rode the same and I was running D load rated ridge grapplers to help with the ride. It was really bouncy like it was ricocheting off everything it hit and a constant vibration around 70 like an out of balance tire (had all wheels checked for being out of round and multiple balances from 2 different shops) and the worst was a harsh vibration under load in AWD mode. It wasnt terrible around town so not a huge deal for the last year while I have been home but I always suspected that leveling it wasnt a good idea.

 

I just traded it a few weeks ago for a new 2021 AT4 that the dealer sent off for a proper lift. Its running a Fabtech kit with dirt logic 2.5 coilovers up front and 2.25s in the rear. Its advertised as a 4 inch lift over the stock 2 inch but the rear block went from 2 to 5 so I think its more of a 3 inch lift with the front leveled plus 35s so thats where I think the full 4 inches over stock comes in. This setup came with new UCAs, steering knuckles, chassis braces to properly move the differential down, etc. For wheels and tires I chose 18x9 fuels with Open Country AT3s which are 35x12.5x18. I've put 1K miles on it so far and can say without a doubt that it rides nearly as good as my stock Denali on OEM 22s with highway tires did before I leveled it. This is with my new AT4 also running an E load rated tire. These coilovers make quite a different up front and 0 vibration at any speed in any drive mode now. I know its unfair to compare given the huge difference in cost but after having messed with my old one for the last year and being convinced that leveling it threw too many things off, this basically confirmed what I always suspected.