Jump to content

2021Chevy Silverado LT will GMC2021 AT4 tires and rims fit

Spuds1701

By Spuds1701
in Modifications, Wheels & Tires

 Share

Recommended Posts

Spuds1701 New Member

Spuds1701

Posted
Posted

Dumb question but I have a 2021 Chevy Silverado LT. I have an opportunity to get some 2021 GMC at4 20in tires and rims. I was wondering if anybody's had experience installing these? Do they need any modifications? My current tire size is 255/70r17 and the AT4 are 265/60r20

Transient Senior Enthusiast

Transient

Posted
Posted

31s versus 32.5.  That's a good question that I don't have the answer to.  You could always add the AT4 lift kit to be safe.  And, the bigger wheel/tire means you'd need to recalibrate the speedo.  Since they're factory size wheels and tires you might be able to get that done at the dealer. 

RedLT Enthusiast

RedLT

Posted
Posted (edited)

My 2021 Silverado LT came with 275/60 20. Fitment wise there's no issue. Not lifted.

Edited by RedLT
Ricky_Starbucks Enthusiast

Ricky_Starbucks

Posted
Posted
13 hours ago, Transient said:

31s versus 32.5.  That's a good question that I don't have the answer to.  You could always add the AT4 lift kit to be safe.  And, the bigger wheel/tire means you'd need to recalibrate the speedo.  Since they're factory size wheels and tires you might be able to get that done at the dealer. 

@Spuds1701, let us know if you have luck with getting a dealer to do the recalibration Transient is talking about.  I went to war with my dealership I made the purchase from to no avail.  They said that GM wouldn't give them the code since I had a 17" spare...which is also what comes when you get the truck with 20s.  (Albeit a different tire size, but they specifically told be because of the 17" spare, not the tire size.). The TSB for the recalibration is PIT3271K.

 

Im still trying dealerships, I have one that said they can do the recalibration for $80, but I'm trying to find more than one that can tell me yes.

 

Good luck!

 

Transient Senior Enthusiast

Transient

Posted
Posted (edited)
9 hours ago, Ricky_Starbucks said:

@Spuds1701, let us know if you have luck with getting a dealer to do the recalibration Transient is talking about.  I went to war with my dealership I made the purchase from to no avail.  They said that GM wouldn't give them the code since I had a 17" spare...which is also what comes when you get the truck with 20s.  (Albeit a different tire size, but they specifically told be because of the 17" spare, not the tire size.). The TSB for the recalibration is PIT3271K.

 

Im still trying dealerships, I have one that said they can do the recalibration for $80, but I'm trying to find more than one that can tell me yes.

 

Good luck!

 

My Trail Boss LT came with a 17" spare, but 18s are on all 4 corners.  Dealers using that as a justification to not do something is just being stupid.  What will they say if I want to put 20s out 22s on my truck?  "Nope.  Won't do it because you have a 17" spare."  Tarradiddle defined. 

Edited by Transient
  • Like 1
Gangly Senior Enthusiast

Gangly

Posted
Posted

They will bolt up just fine.  Get your speedometer calibrated if you want to, or don’t.

  • Like 1
  • 4 weeks later...
Ricky_Starbucks Enthusiast

Ricky_Starbucks

Posted
Posted (edited)

I finally just heard back from the dealer on trying to get my speedo recalibrated for AT4 wheels and it was a no go.  the AT4 has 275/60/20 whereas the 20" option on the Silverado was 265/60/20 so they were "told by GM" there was "no software" for this combination on my vehicle.

 

Trying to decide if I want to risk going with a Pulsar or not, though my truck is brand new and I want no Warranty issues if I should need to use Warranty Service.

Edited by Ricky_Starbucks
dgstarr63 Enthusiast

dgstarr63

Posted
Posted

Just be aware that going from a 17" tire to a 20 or 22 will give you a harsher ride. the shorter the sidewall the harder the ride.  I guess that some of you would consider me old fashioned, but I don't understand why anyone would want the 20 or 22  rims. If you live in a cold climate the larger rims could cause issues with using tire chains. Check your owners manual for tire sizes that permit the use of chains. My last two Silverado Z71s came with 18" tires. I find the ride and handling to  be fine with them, my wet traction improved after switching to Michelin Defender tires from the factory  Goodyear's.

crj19 Enthusiast

crj19

Posted
Posted
7 hours ago, Ricky_Starbucks said:

I finally just heard back from the dealer on trying to get my speedo recalibrated for AT4 wheels and it was a no go.  the AT4 has 275/60/20 whereas the 20" option on the Silverado was 265/60/20 so they were "told by GM" there was "no software" for this combination on my vehicle.

 

Trying to decide if I want to risk going with a Pulsar or not, though my truck is brand new and I want no Warranty issues if I should need to use Warranty Service.


Your dealer is incorrect, the stock 20 inch tire size on a Silverado is a 275/60/20 the same as the AT4.  

latreille89 Enthusiast

latreille89

Posted
Posted

Put them on and send it. It’ll fit. Half inch here or there isn’t going to do much. My winters are a 1/2” smaller because I have the factory 20” rims with a 33” tire on my LT and I went with an 18” steelie for winter. Try finding a common 33” winter tire thats reasonably priced and fits a 18” rim. 265/70/18 was the closest that was somewhat common size. 
 

Keep in mind, you go from a road tire to an a/t tire, both the same size in paper, they will probably sit different on the truck. As they wear they’ll change too. 

Ricky_Starbucks Enthusiast

Ricky_Starbucks

Posted
Posted
10 hours ago, crj19 said:


Your dealer is incorrect, the stock 20 inch tire size on a Silverado is a 275/60/20 the same as the AT4.  

Perhaps they are going strictly by my Trail Boss LT Trim level?  If I go to PIT3271K and follow their instructions, the following screenshot is the build out from Chevy website with the 20" option on a Trail Boss LT showing 265/60/20 and not the 275/60/20.  No idea why Trim Level would dictate this, especially since the TB comes with factory lift and would have no issues with larger tires.

 

I get everyone saying it is OK to throw them on, I was just trying to do my due diligence to have everything done right as if it were with the 20s from the factory.

Screen Shot 2022-01-28 at 9.31.51 AM.png

crj19 Enthusiast

crj19

Posted
Posted
2 hours ago, Ricky_Starbucks said:

Perhaps they are going strictly by my Trail Boss LT Trim level?  If I go to PIT3271K and follow their instructions, the following screenshot is the build out from Chevy website with the 20" option on a Trail Boss LT showing 265/60/20 and not the 275/60/20.  No idea why Trim Level would dictate this, especially since the TB comes with factory lift and would have no issues with larger tires.

 

I get everyone saying it is OK to throw them on, I was just trying to do my due diligence to have everything done right as if it were with the 20s from the factory.

Screen Shot 2022-01-28 at 9.31.51 AM.png

 

My 2021 RST Z71 has 275/60/20, from Chevy website.

 

image.thumb.png.2f5e0e3363b3f4aea155025735aec1a5.png

Ricky_Starbucks Enthusiast

Ricky_Starbucks

Posted
Posted
11 minutes ago, crj19 said:

 

My 2021 RST Z71 has 275/60/20, from Chevy website.

 

image.thumb.png.2f5e0e3363b3f4aea155025735aec1a5.png

 

I guess it is trim level based then, and even though it is avail on other trims dealer (or GM) is being hard about it.  Seems I have wasted enough time trying to do it thru the dealer and will either just install or grab PULSAR LT and go that route.

fastk9dad Enthusiast

fastk9dad

Posted
Posted
On 1/27/2022 at 3:13 PM, Ricky_Starbucks said:

Trying to decide if I want to risk going with a Pulsar or not, though my truck is brand new and I want no Warranty issues if I should need to use Warranty Service.

 

Hypertech also has a module just for speedo recalibration, plug and play as well, if you don't need or want all the features of the Pulsar. I think Rough Country sells a Hypertech rebranded model too.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • Chuck FB
      Fluid Change Questions

      By Chuck FB · Posted

      There would be one way of determining the quality of the factory oil although probably more than a typical oil lab test, and that would be to draw out some oil from a new truck and send a sample to a lab that could do a more elaborate test of the oil. The issue with too little oil in the diff may not be the lack of lubrication of the diff bearings and gears themselves ( although a lack of oil volume for cooling ) but the wheel bearings because at some point the oil would be too low to properly get onto the spinning axle or fed along the axle tube. That was the claim by the local dealer from a couple of trucks in recent years that had the wheel bearings fail and they figured from lack of sufficient oil due to a severe underfilled diff and some of the bearing material made its way to the diff and it got damaged as well so the axle housings were just replaced on warranty. But your right that if the diff is over filled by whatever margin that it causes more churning of the oil than is desirable and that is no good either and can cause a pinion seal to leak. Also old oil I believe can tend to loose some of its properties like antifoaming and another good reason to change the diff oil every so often. 
    • Z45
      Fluid Change Questions

      By Z45 · Posted

      I would be surprised if the diff's were not filled (with the cheapest gear lube) at the axle factory before being shipped to GM.  If you ever watched them building trucks they install the axles and all suspension parts with the frame upside down and then turn it over before its time to install the engine.     Too much gear lube in a axle can be worse than not enough especially with a lower quality GL where is get whipped up with entrained air (foam)  weakening its ability to lubricate.        
    • MORSNO
      Oil Consumption

      By MORSNO · Posted

      This is the 6.6 gasser section of the forum, you should either delete or modify your previous post as it is misleading for anyone looking for factual information on their 6.6 gas engine.
    • Atlas
      Wow I'm in a pickle. (Broke down truck) and a story.

      By Atlas · Posted

      Well....I've done my first intake gasket. Probably wrong, but...we'll see?   Ultra black on the china walls and 1/4" up onto the sides of the intake gaskets. Permatex High Tack (couldn't find Gaskachinch) on the head side of the intake gasket. I read wrong and it says you're supposed to put it on the mating surface of the head, not the gasket. Hoping it's like a PB&J sandwich where it doesn't matter what side the PB goes on so long as there's jelly. That crap is messy/sticky and I got a dab or two on the intake port openings, tried to wipe it off. Hopefully it won't be a big deal and will only aid in sealing.   Per instructions I left the intake (top side) of the gasket dry except for a light smear of RTV around the coolant ports. Wiggling the intake in there was a bear but I had help to free me of surrounding wiring/stuff but I was basically able to set it straight down lined up with the bolt holes.   I did not think to wait until the RTV skinned over but there probably was 5-10 minutes while it sat before installing the intake.   Bolts finger tight first. Then, followed the Chilton's manual pattern to snug them to 15 lb-ft.   Waited a little over an hour, and then did the final torque in sequence again to 35 lb-ft.   Yesterday I replaced the fuel pressure regulator and got my new "nut and bolt kit" (fuel lines) installed. Damn GM used security torx on the spider, which I don't have, so I got scammed at the local HW store for an off-brand security Torx bit set.   The new driver's door mirror arrived yesterday, so, there's a chance this thing could be running and road legal tomorrow? I don't want to get my hopes up.   This will be my first time stabbing a distributor, too. Although, lucky me, someone else marked the old distributor for removal previously, I did see that. (Someone's been here before!!). Engine is still at TDC so it *should* be just a matter of transferring the mark to the new dizzy and rotating it into place.
    • KARNUT
      2027 GMC Sierra: Official Discussion

      By KARNUT · Posted

      He has his dad’s newer truck he’s put away. He has several old cars he rotates between him and his family. I’ve seen a restored square body and a SS Chevy truck he’s sometimes drives. He did raffle off a new suburban recently. As much as he is watched if he drove new stuff as a rule we’d know it. It would be fine by me. I don’t care what people prefer. I got one more new one in me. I’d rather my wife get one. I can’t get her out of the Genesis. Don’t tell anyone. I want her to get an electric truck. I want to put a generator in the back. Just because. She hasn’t bit yet.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...