What's in a factory AT4 lift?

[CrashTestDummy]

We just took delivery of a '25 Sierra 1500 AT4. While I'm working on trying to find a forum similar to this one for the pickups, I figured I'd ask here. Does anyone know what parts are different between the AT4 lift and a 'regular' 4X4 suspension w/o mag ride? I know there's a 2" lift block between the rear spring and diff in the back, but don't know if the front strut, or spring, or maybe a spacer are different in the front. Anyone know?

I want to drop the truck at least 2", to help with us and the pups getting in and out, so am looking to get the right parts for that project. Thanks.

 

[Doubeleive]

We just took delivery of a '25 Sierra 1500 AT4. While I'm working on trying to find a forum similar to this one for the pickups, I figured I'd ask here. Does anyone know what parts are different between the AT4 lift and a 'regular' 4X4 suspension w/o mag ride? I know there's a 2" lift block between the rear spring and diff in the back, but don't know if the front strut, or spring, or maybe a spacer are different in the front. Anyone know?

I want to drop the truck at least 2", to help with us and the pups getting in and out, so am looking to get the right parts for that project. Thanks.

I would gamble and say your probably going to just have to do a visual inspection to see which is the case. Probably not many people on any forum looking to modify a new out the gate vehicle, I mean people do but a lot of that is done with aftermarket parts and it usually takes 3rd party company's a minute to get something to market, depending on how many changes have been made from previous years,

 

[CrashTestDummy]

Yep. Just asking, in case I'm not blazing a new trail. I have a friend we autocross with who has a Denali Ultimate, and next time we see them at an event, I'll crawl under the front of the truck with a tape measure/camera and see if I can spot anything obvious. Just figured while I was here......

 

[d_hawk]

You can buy the AT4/Trailboss kit from GM and install after the fact.

https://www.chevypartspros.com/sku/85040013.html?srsltid=AfmBOopR1k2yhaH0zbEa9USsHVZoGhCXPadi_tMbAlnIDx5x-o5gsOma

 

[CrashTestDummy]

I've seen that. Based on that, I'm guessing we'll have to get at least new front struts and half shafts for the front, and the elusive squared-off shorter spring clamps for the rear. Guess we'll also have to verify the rear shocks still have range of motion when mounted 2" shorter.

 

[Trey Hardy]

I've seen that. Based on that, I'm guessing we'll have to get at least new front struts and half shafts for the front, and the elusive squared-off shorter spring clamps for the rear. Guess we'll also have to verify the rear shocks still have range of motion when mounted 2" shorter.

I know when I got my coil overs they came off a at4 and I put them on my 07 and instead of 3.5” they were like 5.5” of lift I ended up putting a 3” leveling kit on top of them and used them when I installed my lift kit
From my understanding it’s just the shocks rear blocks and cv axles that may be 2” longer then stock

 

[ProfeZZor X]

Wait a sec... you want to DROP an AT4?

 

[Marky Dissod]

We just took delivery of a '25 Sierra 1500 AT4. While I'm working on trying to find a forum similar to this one for the pickups, I figured I'd ask here.
Does anyone know what parts are different between the AT4 lift and a 'regular' 4X4 suspension w/o mag ride?
I know there's a 2" lift block between the rear spring and diff in the back, but don't know if the front strut, or spring, or maybe a spacer are different in the front.
Anyone know?
I want to drop the truck at least 2", to help with us and the pups getting in and out, so am looking to get the right parts for that project.

My guess is you'd look at non-AT4 Sierras? - maybe a Z71, or maybe another different, slightly less tall Sierra?
If you find one whose stance suits you better, get that VIN, so you can compare parts lists against your VIN @

Free GM Vin Decoder | GMPartsGiant

Free GM VIN Decoder - Do a VIN lookup to acquire specific car information. Ordering exact-fit parts has never been this smooth and hassle-free on GMPartsGiant!

www.gmpartsgiant.com

 

[tooleyondeck]

I'm curious as to what an AT4 had that an otherwise non-lifted SLE/SLT/Denali wouldn't have?

I've been on this forum for a few years, I don't think any forum will be comparable to TYF, but it is pretty active:

Chevy Silverado and GMC Sierra Forum

A forum community dedicated to Chevrolet Silverado and GMC Sierra pickup owners and enthusiasts. Come join the discussion about performance, modifications, classifieds, troubleshooting, maintenance, and more!

www.silveradosierra.com

 

[Dirty looks]

Wait a sec... you want to DROP an AT4?

Seems like buying a regular Sierra with extra steps.

 

[olyelr]

I see this post is a year old, so you may have already figured it out.

But I would consider finding a friend with a newer non at4 and swapping the shocks/springs out.

 

[CrashTestDummy]

Wait a sec... you want to DROP an AT4?

Yes! It's a tow rig for our race car and we wanted to be able to use it as a toad for our motorhome. It's also my 'pup mobile' that we use to haul our dogs in. As we, and they age, climbing a set of stairs to get in and out will become a big deal.

I went around and around the 'GM options ordering pachinko machine', and to get the options I wanted (6.2 2-speed transfer case, 4WD, CC short bed that would fit the garage, among other things) AND options I didn't want (sunroof, Denali package, among other things), this is what I arrived at. I don't need a lift, it'll NEVER be off road, except maybe in a gravel parking lot, or field to retrieve a trailer.

The rear suspension has 2" lift spacers between the spring and axle. I have the appropriate round, shorter, u-bolts in possession now, and will see if that helps the ride height some, and doesn't look too stupid before I can figure out the front end, which appears to be new half-shafts and struts. It looks like the back is indeed 2" higher than the front, but you really can't tell exactly how much. Hoping to NOT get a Carolina stance with the new u-bolts. I'll get a visual when I do that project.

And no, I don't have a definite solution yet. I have a friend we race with that has a '26 Denali, so I'll get his VIN next time I see him and see what a parts comparison shows. After I get it down to 'not lifted' level, I plan to get a 2/3 drop kit for it. Thanks.

 

[olyelr]

Yes! It's a tow rig for our race car and we wanted to be able to use it as a toad for our motorhome. It's also my 'pup mobile' that we use to haul our dogs in. As we, and they age, climbing a set of stairs to get in and out will become a big deal.

I went around and around the 'GM options ordering pachinko machine', and to get the options I wanted (6.2 2-speed transfer case, 4WD, CC short bed that would fit the garage, among other things) AND options I didn't want (sunroof, Denali package, among other things), this is what I arrived at. I don't need a lift, it'll NEVER be off road, except maybe in a gravel parking lot, or field to retrieve a trailer.

The rear suspension has 2" lift spacers between the spring and axle. I have the appropriate round, shorter, u-bolts in possession now, and will see if that helps the ride height some, and doesn't look too stupid before I can figure out the front end, which appears to be new half-shafts and struts. It looks like the back is indeed 2" higher than the front, but you really can't tell exactly how much. Hoping to NOT get a Carolina stance with the new u-bolts. I'll get a visual when I do that project.

And no, I don't have a definite solution yet. I have a friend we race with that has a '26 Denali, so I'll get his VIN next time I see him and see what a parts comparison shows. After I get it down to 'not lifted' level, I plan to get a 2/3 drop kit for it. Thanks.

Depending of what type of 2/3 drop you go with, you might be wasting your time going to non at4 ride height, as some of the components you change out to get to that point may need to be changed out to get lowered.

Lowering an at4 sounds asinine, but i completely understand how you got to this point.

I would determine what type of lowering kit you want to go with before spending any time trying to get it to non at4 stance. The kit may come with new springs/struts already anyway.

I dont believe the axle shafts would need to be changed out. They are most likely just a little beefier and/or are able to operate at a steeper angle for the added height.

 

[olyelr]

Yes! It's a tow rig for our race car and we wanted to be able to use it as a toad for our motorhome. It's also my 'pup mobile' that we use to haul our dogs in. As we, and they age, climbing a set of stairs to get in and out will become a big deal.

I went around and around the 'GM options ordering pachinko machine', and to get the options I wanted (6.2 2-speed transfer case, 4WD, CC short bed that would fit the garage, among other things) AND options I didn't want (sunroof, Denali package, among other things), this is what I arrived at. I don't need a lift, it'll NEVER be off road, except maybe in a gravel parking lot, or field to retrieve a trailer.

The rear suspension has 2" lift spacers between the spring and axle. I have the appropriate round, shorter, u-bolts in possession now, and will see if that helps the ride height some, and doesn't look too stupid before I can figure out the front end, which appears to be new half-shafts and struts. It looks like the back is indeed 2" higher than the front, but you really can't tell exactly how much. Hoping to NOT get a Carolina stance with the new u-bolts. I'll get a visual when I do that project.

And no, I don't have a definite solution yet. I have a friend we race with that has a '26 Denali, so I'll get his VIN next time I see him and see what a parts comparison shows. After I get it down to 'not lifted' level, I plan to get a 2/3 drop kit for it. Thanks.

A guy in this thread claims he lowered his at4 4” all around.

He said he did replace the axle shafts.

AT4 "Lowering Kit"

www.gm-trucks.com

 

[CrashTestDummy]

I'll have a look. Thank you!