jbr1888

My 2019 X31CCSB SLT 6.2 definitely has a shim. Looks to be about 1/4 inch on the fat end a 1/16 on the small end. Maybe the heavier 6.2 requires that tiny rear shim to maintain the correct height? If every other suspension component is the same as the 5.3, and I think it is, it would sit some measure lower.

Does anyone know the thickness of the shim that comes on the 2019 X31 and Z71 trucks where the prior generation had a an actual lift block in the rear? You can see the shim these trucks use in this video @14:53:

That tire will not measure the same size as the spec sheet when it is mounted and under the truck's weight. I just measured Atturo Trail Blade XT 35 x 12.5 on a late model Ram 1500. They were 33.25 inches tall on the truck. Atturo says that tire is 34.8 x 12.5.

I have had my truck (SLT X31 CCSB 6.2) since November, and for a while I've been noticing a popping sound coming from behind the cab, can't really tell which side, when I drive over dips or bumps on the diagonal. It seems worse in reverse. My driveway meets the road in a way that means every time I leave, I turn and drive through the valley where the road and driveway meet at basically a 45 degree angle. This causes the truck to flex slightly and that's when the popping happens. Its loud enough to hear inside the cab, but its not super loud. For a while I assumed it was stuff rolling around in the bed, that's kind of what it sounds like. Anyone else have anything like this going on?

Gotcha. I wasn't sure how far toward the frame that bracket extended.

Did you remove the steel bracket behind the plastic mud flap?

This is a good guide for what you need to modify.https://wheelsasap.com/gmc-at4-oversized-tire-trimming-guide/ I'd start by removing the bracket and pulling the flap and wheel well liner back as far as you can. Several folks have said you don't have to trim so much. I'll be doing this very soon myself. Here's a link to what another guy said he did on his Sierra:

Those do look like the factory 20s.

2019 Sierra SLT Crew Cab 1500 X31 6.2L with 13k miles. The truck has frequently made noises after I turn it off and inexplicably applied the parking brake. The noises sound like relays or servos clicking and humming. They're pretty loud. Then today I got in it drive home from work, and saw the CEL. I used my OBD2 device to read the codes and got Codes P25A2 - U0101/100/146.

Superlift uses Bilstein 33185569 (which is 29.7 extended and 17.9 collapsed) in their 3 inch lift for the T1 trucks. That kit uses a 1.5 inch rear block. I bet they'd work just fine with your 2 inch rear blocks. Otherwise, I'd find the model that's .25 to .5 inches longer.

RC sells the UCAs on their website. I think the 1.5 level on a TB or AT4 would be the same as a 3.5 RC lift from an angle standpoint since those trims start out 2 inches higher with the same UCAs as the non-TB or non-AT4.

Tires aren't about lift. That'd be the most expensive lift possible. They're supposedly about more offroad capability for all that mall crawling. LoL. They also improve the truck's look because they look more aggressive. But to each his own.

With my 2 inch level, my 275/60R20 Revo 3's, are already only half an inch or so from the UCA. 285/60R20 KO2s will fit with absolutely no problem, my buddy is running those on his leveled truck, and they are 33.5 x 11.2 on their spec sheet, again the factory Revo 3's are nominally 33 x 10.8. I don't see how you can run anything wider than the 11.5ish on OEM 28mm offset wheels without spacers. Here's a photo of how close the 275/60R20 Revo 3's are to the UCA at full lock.

This is really great to know. Thank you for the write up and the pictures. It will be very helpful.

Can anyone measure and post the actual height and width of your 285/65R20 or 35x11.5 Trail Grapplers mounted on your T1? I'm expecting they'll be about 34 x 13.5 when actually on the truck.

He said he had a 2 inch level. Also, even at the stock ride height, the wheel well width, front to back, is the real limiting factor. Even stock, I think there's about 5 inches from the top of the tire to the fender.

I have spent soooooo much time researching this exact issue over the last month. Go look at @2019sierra on Instagram. You'll see leveled trucks running all kinds of tires. It'll give you some ideas. All of this assumes you're running OEM wheels with a 28mm offset, like your Elevation wheels. The biggest thing you have keep in mind though is the P metric tire sizes mean absolutely nothing to tire companies. So, you have to look at the specific physical measurement of each tire. For example, 295/60R20 equates to 33.9" x 11.66," BUT a Nitto Trail Grappler 295/60R20 is 34.45" x 12.13" while a Nitto Ridge Grappler in 295/60R20 is 33.94" v 11.77." That specific tire definitely fits without trimming, based on my research. The Trail Grappler requires light trimming to plastic behind the front valence and requires cutting about half of the front mud flap off and removing the steel mud flap bracket. Here is the holy grail guide for this procedure: https://wheelsasap.com/gmc-at4-oversized-tire-trimming-guide/ Based on my research and actually reaching out to some guys online that are running 35x12.50, 35x11.50, and the 34.45" x 12.13" Trail Grappler, all on non-AT4 Sierras with a 2 inch front level, you can fit that 295/60R20 without trimming as long as it's 33.94" v 11.77" or smaller. With that said, I believe narrower tires such 285 or 11.5 are much less likely to rub. With the 295 and wider, some folks have said you'll need a 1/4 inch spacer for the front wheels to clear the upper control arm. I've ordered a set just in case. I'm trying to decide between the 285/65R20 and 35x11.5 Ridge Grapplers for my 2 inch leveled 2019 SLT X31. Finally, as if each different tire model of a same P metric size (295/60R20, for example) wasn't a different size in real life, the physical sizes listed by the manufacturer or tire store websites is for the unloaded tire. This means that once the tire is mounted on your truck and is supporting your truck's weight, the tire's dimensions will be different, usually smaller in height and wider in width from sidewall to sidewall. For example, my factory Bridgestone Revo 3's are 275/60R20, they should be 33" x 10.8". On my truck and filled with 38lbs of air, they measure 32" x 12.75." So, they're nearly 2 inches wider than their spec. Hope this helps.

Would these work? https://www.4wheelparts.com/p/bilstein-b8-5100-series-shock-absorber-33-253237/_/R-BBGL-33-253237 They are a hair shorter than the ones for the Trailboss. I have a 2 inch front level and a 1 inch rear lift block.

Good to know. Thanks. I'm still curious if anyone has done it without the preload spacer?

Has anyone lifted their T1 3 or 3.5 inches with only strut spacers and control arms without adding preload spacers? I want to install the lift myself (its definitely something I can handle). However, I don't have access to a strut compression machine. I've read that the all-thread type compressors are very difficult to use on these springs, and I don't want to get my truck torn down and then not be able to get the strut apart to insert the preload spacers.

Did you replace the rear shocks? Also, what tires did you wind up using? And, do you have any thoughts on whether this kit adds additional wear to the front end? Have you tried driving in auto 4-Hi? I'd really appreciate the info.

Does anyone have anymore info about the comma.ai system for the 2019 new body style 1500 trucks with LKA? Specifically, why will it not work? Has any work been done towards making it work?