Supercup

Thanks - did not see those two tags when i looked last night in dark. Mine was 7/20 build - is a late 2020. So right in the middle of the time frame - 3,000 miles so far - no issues - goes into dealer tomorrow for fluid service

Is that photo with sumo springs in use - you are right on top of the bump stop. I have 2020 AT4 and tow quite a bit. Been looking at this option to help with tongue weight of car trailer - have load leveling hitch and that helps a lot, but looking for something more. Last truck (14 Raptor) I did Deaver spring pack and they custom tuned for tongue weight - so worked great, eliminated the rear block etc. But $1,200 for spring pack, which is more than I want to spend if sumo spring will for a few hundred dollars. Thx for any more info.

Interested in figuring out the build date on my truck - anyone able to direct me to source for that. Traded my 2019 AT4 for a 2020 to get trailer tow mirrors - in August 2020. So far have 3,000 miles - no issues - but would be interested to know if it was built before the June date. Would hate to get stranded towing with the Family. Also in reading through thread seems like a lot of failures within a few hundred miles of new - any failures with higher mileage trucks?

Below is a photo of my 2019 AT4 with 2" Ready Lift SST level kit - so 4" over a stock truck. Note CV angles are pretty extreme for level ground. Also note that RL has on their website a note that states - they don't recomment you use auto 4WD with this kit as they have customers who did and toasted the front diff due to torque of shift on the fly and poor geometry. There are potential issues for your front diff with any level over 2" and common knowledge with experience shops that over 3.5" you will likley have problems sometime down the road - I went 11k on my 2019 with no ill effects, but never used auto 4WD. Losing a feature on your truck like that is not ideal. If you go with a proper lift kit that drops the front diff, you can go 4" or 6" no problem - see photo #2 of my 2020 AT4 (traded to get trailer tow mirros and good camera stuff for towing). This is a BDS lift kit of 2.5" - so on an AT4 that is 4.5" over a stock truck - note the axels are pretty much level - which is what you want. You can get proper lift kit from rough country, zone (owned by BDS but a bit less expensive) or BDS without shocks and you will spend about twice as much as a level kit - but you will not have any issues down the road. 2019 AT4 - note angle of CV axel boots 2020 AT4 - BDS 2.5" Lift Kit

I have these off my 2020 AT4 if Interested ping me. Came off at 1,500 miles when I put on BDS coil over lift, which came with its own skid plates

BUMP

Yes that is the lift I went with - not too extreme, still good for towing and everyday use. Note the large front skid plate that has BDS cut out, was not installed on my truck. The shop that installed stated they have to remove the airdam under the bumper to install and found that it created a large amount of air noise that customers complained about, so they did not recommend putting it on, unless doing a ton of offroad stuff. So I left it off on mine. Here are a few photos

'Yes - any level kit will cause this type of axel angle. Only proper lift kits with diff drop brackets will give you level CV's like the BDS I put in.

Hi, You may want to "re-post" this in the section for 1500 trucks - this is the HD section. I have 2020 AT4 - and tow quite a bit - I find the tires and rear springs a bit soft and you do get some sway, certainly more than prior trucks I owned. I have found with sway control bars and load level hitch most of the problem was solved. I still have the stock load range C duratracs. Going to load range E tires with stiffer sidewall will help as well. Not likely you would run pressures anywhere near the 80 lbs you mentioned - most likely when towing around 50-60 psi. I don't think that will be issue for your system, as I run 60 lbs on goodyear trailer tires with sensors reading in the truck no problem. think you may find that the tires will have an impact, but not as much of an impact as adding sway control bars and load leveling hitch to your trailer and updating your rear springs, either with adding sumo springs (cheap fix) or a new custom spring pack from Deaver Springs. I am towing a toy box (10 k loaded , 6,500 empty - 1,200 lbs tongue weight) and a Intech race car trailer (9,000 lbs loaded, 4,500 empty - 1,000 lbs of tongue weight) I had a 2014 Raptor before and it had similar issues. I found that addressing the issue in the order below gave me a good idea of what each item did for me. I did it in steps as follows with 2014 Raptor which had BFG KO2 35" tires load range D: 1. Sway Control bar and load leveling hitch - net result - 1.25" less sqaut under tongue weight - big improvement overall - overall cost $550 2. Second sway control bar on trailer - net result - small improvement - limited sway to wind situations - overall cost $50 3. Deaver custom rear spring pack - net result - reduced squat (without load level hitch) from 1.5" stock to about 0.50" - big improvement in ride (loaded and unloaded) better trailer control - $1,100 For 2019 AT4 I did the following: - Had Ready Lift SST 2" level kit 1. Sway Control bar and load leveling hitch - net result - 1.00" less sqaut under tongue weight - big improvement overall - overall cost $550 2. Second sway control bar on trailer - net result - small improvement - limited sway to wind situations - overall cost $50 I traded the my 2019 for a 2020 AT4 to get Trailer Tow Mirrors and Camera tech and did the following: 1. Sway Control bar and load leveling hitch - net result - 1.00" less sqaut under tongue weight - big improvement overall - overall cost none - transferred from 2019 2. Second sway control bar on trailer - net result - small improvement - limited sway to wind situations - overall cost none - transferred from 2019 3. BDS 2.5" lift - 2.5" coilover front shocks (adj) with 2.0 (non adj) rear shocks - stock springs - overall cost $5k - net result - great improvement in truck on and off road - for towing - a little better control but not a ton of added impact - so net effect is this suspension benefits me when not towing on and off road. I plan to add sumo springs to the rear next, to see if that carries the tongue weight better - they area cheap alternatiave to Deaver Springs I also plan to go with KO2's when I need new tires. Good luck finding the right solution.

I would say 1.5" (3.5" overall) is max, anything over that should have a proper lift kit. Here is a photo of my 2019 AT4 with 2" level kit (so 4" overall) and you can see the angles are pretty extreme. The mfg. - Ready Lift, recommended that you "not" use 4wd auto due to angles potentially causing front diff damage. Below that is my 2020 AT4 with 2.5" BDS lift kit, with diff drop brackets, - you can see the CV's are dead level. For me I would say even if you don't upgrade your shocks, get a 2" proper lift kit to level the truck - will cost more, but long term you will never suffer front failure due to CV Angles. Happy Thanksgiving! 2019 Ready Lift SST 2" level kit with UCA 2020 With BDS 2.5" lift kit

For Sale 2020 GMC AT4 - OEM 18" x 9" wheels - $1,150 OBO (taken off when new - 20 miles on them +/-) - no tires Fits any 2019 or 2020 GMC Sierra 1500 or Chevy 1500 Prefer S.Cal sale - I am in Orange County and am frequently in San Diego Wheels can be shipped in boxes (method boxes) at buyers expense Thx for looking - reasonable offers considered from people standing in front of me with cash , no trades.

I have 2020 AT4 - took off the Rancho Shock and other related products to install BDS 2.5" lift with Fox Coilovers. If anyone is intersted I am selling the take off parts and skid plates as a package for $500 for S. Cal Local Pick Only - so no time to figure out shipping for something large or heavy. I am in Orange County and am frequently in San Diego for anyone intereted. Shocks, springs (front), steering knucles, rear blocks, two front skid plates, rear block U brackets and bolts Parts taken off at 1,574 mies from new. I also have OEM 18" wheels - they have 20 miles on them - taken off when new as well. Link to ad: I PM me if interested. Thx

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

Here is the issue - you start with 2" of OEM lift - you add 2" level kit with RL SST kit. It is a nice kit - had it on my 2019 GMC AT4 Carbon Pro. They have a note in there than you "should not use auto 4wd" with the level - issue is the angle of the CV axels is pretty extreme and they had some customers with issues with auto 4wd shifting in and out at various speeds and putting heavy load on front diff due to angles of axels and cv's. I ran my 2019 for10k miles with it, had no issues, but never used auto 4wd. Not ideal, but as good as any other level. When you call knowledgeable offroad shops it is common knowledge (to them) that anything over 4" of lift really needs a drop bracket for the front diff. So level kits on AT4 and Trial Boss are at that edge. I swapped my 2019 for a 2020 with trailer tow mirrors and better camera tech for trailering. I decided to do it right and went with BDS lift kit, which lowers the front diff - so the axels are dead level. I posted some photos below so you can see the difference in angles for yourself. BDS and Zone (who is owned by BDS, but their lower cost brand) offer a 2.5" lift kit for AT4/Trail Boss (so 4.5" of total lift) that lowers the front diff without coilover shocks - other do as well- it is more expensive way to go than RL( RL SST kit can be purchased from Tire Rack for $507 - Zone lift kit no shocks is $1,313), but install is a about the same, but given the better axel angles and no issues with auto 4wd this may be the best way to go. I was able to step up the adjustable coilovers and it was expensive, but well worth the dollars - works great on and off road. link: https://zoneoffroad.com/search?fitment=1 Link: https://bds-suspension.com/product?ma=5&mo=1&ty=113&yr=2019-2021&kid=754F Good luck finding good solution for you. If you do a search there are a number of threads on this topic and lots of photos. READY LIFT - CV AXEL ANGLES - 2019 AT4 - SST KIT - STOCK 275/65/18 DURATRAC TIRES 2020 GMC AT4 - BDS COIL OVER 2.5" (4.5" OVERALL) LIFT KIT AXEL - DEAD LEVEL WHEEL QUESTION - DON'T KNOW ABOUT 20'S BUT FOR REF - THIS IS 275/65/18 ON METHOD NV 18X9 W 18MM OFFSET - ONLY ABOUT 5/8'S OF AN INCH CLEARANCE TO UCA

Last Few first one - front 2/3 turn second one - rear of tire full lock last one - front of tire - 2/3 lock - closest pinch point - will rub over - larger tires would need this area trimmed.

A few more first - front of tire 2/3 turn second - front of tire full lock third - front of tire full lock fourth - front of tire full lock - just barely misses wheel liner

Here are a few more photos of tire clearance - with stock 275/65/18 Duratrac's on Method 18 x 9 wheels with 18mm offset - 2.5" BDS Coilover lift on 2020 AT4. first one - front tire - front clearance - straight wheel - looking inside out. Second one - front clearance - straight wheel - back of tire third - front clearance - straight sheel - front of tire fourth - front clearance - 2/3rd turn of wheel - front of tire fifth - same as fourth - view further away

I have a 2020 GMC AT4 - I installed 2.5" BDS coilover lift (so 4.5" overall)- it will work with stock 20" wheels - but not likely with stock 18". the AT4 18" is 26mm offset (5.75" of backspacing +/-) - so the tie rod from the BDS lift hits the edge of the wheel and tire, so you have to push the wheel out. I have Method 18x9 NV wheels with 18 mm offset (so about 1/2" more inside clearance - 5.25" of backspacing than stock). I tried a 1.25" extension - did not clear - so we ended up doing wheel lug extensions and getting enough bite on lugs to make it work, but I would not consider it ideal. You need an 18" wheel with 4.5" of backspacing. On the 20" wheel the added diameter allows for the tie rod to be "inside" the radius of the wheel, so you can run stock 20's or other 20's with up to 5.5" of back spacing. I would confirm the offset of your stock Trail Boss wheels - if 26mm like the GMC AT4, you will have a tough time making it work without new wheels. I can tell you that the suspension performs very well on road and is night and day difference off road. If you go that route be sure and get the DSC upgrade so you can adjust compression and rebound to your driving conditions! Here is a few threads about it with photos and showing you clearance issues. Note I had a 2019 AT4 with Ready Lift SST kit before and the CV angles were really bad - with BDS, it is dead level. I would definately go that route, even if you just buy the lift initially and add shocks later, to get the level axels. Link: Link:

Tough question to answer - the OEM mono tube Rancho's actually ride pretty good on the street. They are way too soft for off road blowing through the stroke very quickly and bottoming out. But overall I found the OEM ride quality to be very good on the street. The Fox/BDS set up is more flexible with DSC adjustments on front shocks for compression and rebound - at full soft or a few clicks odd the ride is excellent, however it is "firmer" than stock. I would consider it comfortable, but if you don't like a firm ride, you would think the stock truck was smoother on the street. Off road, no comparison with the better shocks and lots of adjustments you can really dial in the shocks and enjoy the truck. If you like the stock ride - you may think this is too firm - if you don't like the soft stock ride, then this offers the best of all worlds with total dial in flexibility - on the street I run 2 clicks from full soft on compression and rebound right now. Will try softer after some more miles on the shocks and springs for full break in. Overall it meets my needs and expectations and I am glad I did it. I like this set up much better than the Ready Lift SST kit, with stock shocks I had on my 2019. It is not for everybody, but if you are familiar with adj. off road shocks you will be pleased.

I have a 2020 AT4 Carbon Pro - I did the 2.5" lift (so 4.5" overall) with fox 2.5 coilovers - I have Method 18 x 9" NV's with 18mm offset - they did not clear the tie rod, so we had to go with spacer and wheel lug extender to gain about 1.25" of backspacing, so clear the tie rod. The method -12mm would be the recommended fit. With 20" the tie rod will go inside the wheel radius, making that more flexible for offsets. With 17" you will have the same issue I had, but not as bad due to 0 mm offset - might barely fit, but if not with a 1/2" spacer you should be good to go on the tie rod issue. But you will need to do some trimming to fit the 35's. Pinch point will be the front fender where it tapers in - you only have 2" - going with 35" over stock 33's should eat all that up. I will be very interested to see how yours turns out, as I am looking to get new wheels and larger tires - so if you fit 35's will be interesting to see what all is invovled. I still have stock 275/65/18 duratracs on mine. Here are some photos showing clearance - FYI - no issue on inside clearance on steering knuckle for tire - 4" of inboard room at least - so 12.5" section width will be no problem over stock 11".

warranty is 3 years - 36 months on truck - kicker should be covered under that - if issues is not from abuse, your dealer should cover it. I had mine replaced on my 2019 due to "intermittent" connection - sometimes it would and sometimes it would not. Dealer said they had replaced them for a number of different reasons. So I would start with your dealer - good luck!

-12 mm Method 9"x18" clears the tie rod (4.5" backspacing)- question then is will you be able to fit 35" tires - with that offset the wheel is pushed further out. since the 35" is 12.5" wide, same as the 33" they say will fit with this set up, it would seem that the issues on the 35" will be, with it pushed out another 1", versus a 20" will it require "more" trimming or just not fit at all. I can say for certain there is no "tire width" issue on the inside. From the inside of the 275/65/18 I have there is about 4" of inboard clearance (measured with tape). The tie rod also would not interfere with a 2" wider tire. So issue to resolve is the taller height and what is the impact? When I got mine put on they suggested that 33" or 34" would be the way to go with 18's, but never said 35" would not work. The guidance states 35" will fit with 20" with 5.5" - 6.25" pf back spacing - which moves the wheel back in and places the tie rod, within the wheel radius. Can't draw any conclusions - will probably have to be trial and error at the tire shop! Here are a few photos of inside clearance with my current set up with the 275/65/18's - which are 32.3" diameter and 11.0" section width wide. Currently at full lock in reverese the just barely rub on the inside. So no matter what, with this set up larger tires are going to need trimming - bigger you go, the more it will require. Looks to me like the first pinch point is the gap between the "front" of the tire and the lower corner of the front fender - that has about a 2" gap - so if you went up 4" in diameter (31" to 35") you should have 2" of growth on either side (right?). That would put the 35" right up against that front fender. The rear fender gap is 3". I would say if you want to go with 35" tires the 4" kit (which is 6" overall) may be the safer starting point. If I do more tire work, I will post up, but not planning to go bigger, unless I get new wheels. Photos show 1. tie rod clearance 2. Top clearance steering knucle 3. Top clearnace 4. Front fender clearance - two finger - inside out 5. Front fender clearance - inside out 6. Rear fender clearance - outside in 7. Front fender clearance - inside out

2019 did have Ready Lift Upper control arms - however they are not "longer" per say - they just change the angles, to correct the geometry of the upper ball joint, to reduce the wear. Below is video from Ready lift that walks through their AT4/Trail Boss level kit and SST kit. See minute 1:37 - 2:04, 3:55 - 4:20 and 5:20 - 5:40 to hear about control arms. If you stop video at 4:22 you can see the control arms (stock and Ready lift) - if you measure from the bolt hole to the tip and see they are basically the same length. I do agree there are many after market control arms that are longer, but it does not appear to be the case here. Also note the "thicker" end of the RL UCA, reduces tire clearance on the inside versus the stock UCA's - see photo below of clearance with stock 27/65/18's on a 18mm offset Method NV 18"x9" wheel. That photo is my 2019 with RL SST kit installed. With stock wheels, which are 26 mm offset, I could not get my finger in there - too close. That is about 5/16's of an inch of clearance. LINK:

The short answer to the OP's question is that any "level" kit for AT4/Trail boss may impact use of auto 4WD. CV angles with level are to extreme in the front, no matter the level kit mfg. the issue is when the truck moves into 4wd under some conditions the front diff suffers extreme torque and it can be severely damaged. RL added a note to the SST kit after a few months, due to customer complaints of loud noises and a few customers who complained they lost their front diff's when using 4WD auto. When you speak with knowlegable shops they all seem to agree that 4" of lift is the point of no return - so 2" added to AT4 + 2" more. Unfortunately the RL level kit, noted above has no mention of the "auto 4WD" function impact, but their SST kit they have the following note "NOTE: Use of Auto 4 HI feature not recommended", the only difference is the rear block. It is 1.75" level - so 3.75" overall, where SST states it is a 2" level (so 4" overall). The upper control arms correct the angles for the upper ball joints, but do nothing for the CV axel angles. I had a 2019 AT4 Carbon Pro - I installed the RL SST kit - CV angles were not good - no auto 4WD. I traded in for a 2020 AT4 Carbon Pro with trailer tow mirros, as I tow a lot and I did not want any issues up front. Pictures below. For the 2020 I went with BDS 2.5" lift - which provides proper CV angles (better than AT4 from Factory). I have the full program with Fox 2.5 DSC coilover shocks - so a $4,700 deal installed. I love it, but it is a lot of money if you don't go offroad much and just want a level. If you want to use Auto 4WD, you will need a lift kit that lowers your front diff, to keep CV angles within OEM spec. You can buy BDS or Zone 4" lift kit without the Fox shocks and save some $ - but you are still looking at $2,086 for BDS and $1,300 for zone (which is made by BDS). But that is 6" over stock -so 4" over your AT4 OEM ride height - currently they do not offer the 2.5" lift kit without the fox coliovers (which is 4.5" vs stock 4" for AT4). There are other mfg. of proper lift kits as well that can get you same outcome, as long as they have a diff lowering brackets in their lift kit. Zone is the best overall value, for just the lift. RL SST: https://www.readylift.com/at4-trail-boss-plus-2-0-sst-lift-kit-gm-1500-at4-trail-boss-4wd-2019.html BDS: https://bds-suspension.com/product?kid=749H Zone: https://zoneoffroad.com/products/4-in-ifs-suspension-lift-kit-2019-2020-chevy-trail-boss-gmc-at4?variant=33403092729944 Below are photos of my 2019 with RL SST kit and my 2020 with BDS 2.5" kit - you will note the CV angles are level on the BDS and are quite extreme on the RL (note boots). There are no short cuts for AT4/Trailboss to do a proper level or lift. Only other options other have tried is a shorter block in the rear for the level. That is the cheapest option, but may not work the best. 2019 AT4 - Ready Lift SST Kit - CV Angels - level ground 2020 AT4 BDS 2.5" Lift Kit CV angles - level ground 2019 AT4 Stock 2019 SST RL Level - dead level 2020 AT4 BDS 2.5" Lift - Fox shocks - a little rake

Hi, OEM 18" AT4 Wheels I have four (4) OEM GMC AT4 OEM wheels for sale - no tires - taken off the truck at 50 miles +/- - new condition. $1,250 for all four - only selling as complete set - local sale only (Southern California) Suspension: I have OEM knuckles, front Rancho shocks and springs, rear Rancho shocks and lift blocks and skid plates off 2020 AT4 (replaced with BDS lift). Taken off truck at 1,582 miles. $550 - sell as a package only - local sale only (Southern California). - see link to ad on Craigslist, it has lots of photos Link to Craigslist ad for shocks: https://orangecounty.craigslist.org/pts/d/san-juan-capistrano-2020-gmc-sierra-at4/7216378026.html $225 - Chrome Exhaust tips - off 2019 GMC AT4 (swapped out for the black ones). I traded the 2019 in for a 2020 with trailer mirrors (why I have parts for two different years). Can ship these, buyer pays shipping. Reasonable offers considered. Entire bundles for $1,500. email me at [email protected] and I will respond.