Wormydog1724

‘21 Sierra AT4 3.0L dmax Bilstein 5100 front and rear, 1.1” setting Cognito UCA, round Stock 18” wheels Stock Duratrac 275/65r18 tires Still has some rake (I haven’t measured it though), I’d prefer it be more level but I don’t want to mess with any spacers so I guess it is what it is. After these tires are done I want to try 285/70r18, I’m just concerned about the UCA and tire clearance. I like the stock wheels just fine so I don’t really want to change them.

$350 and some change for 5100’s all around and Cognito UCA install. That includes alignment after install.

I got it figured out

2021 Sierra 1500 AT4 3.0L duramax with Bilstein 5100 set to highest level 1.1”, Cognito UCA, stock Duratrac 275/70r18 tires, stock wheels. Just wanting to show the clearance of the Cognito UCA with the stock wheel/tire setup and the CV angle

I would have preferred mine came with CP but it was the color I wanted, the motor I thought I wanted, and it was sitting there ready to roll. I didn’t really care either way but it’s the only option I don’t have, so that makes me want it.

got mine today. Much better. Very happy.

I drive my 3.0L dmax two miles to work, two miles to the gym, two miles back to work, and two miles back home. Only 5k miles on it so far. I’ll report back when I start having issues.

Ok

My father-in-law’s ‘19 AT4 UCA joint sheared two weeks ago. Around 35k miles with a 2” level bottom spacer. It let loose at 75mph and sent him into the ditch, nearly caused him to roll. When he told me it snapped I started asking questions: stock UCA’s, 33” Nitto tires, and he finally tells me 2” spacer installed by a local shop. He farms out of his AT4 so it’s seen some rough ass roads and off road use, hauling a big ass Polaris fourwheeler. I figured it was just him being rough on it, he’s been known to treat his vehicles like ******. But the 2” level and stock UCA was the real culprit. He didn’t like the factory rake so that’s the reason for the level initially. Three weeks ago I installed Cognito UCA’s and Bilstein 5100’s on my ‘21 AT4 and he thought I was silly for doing that to a brand new month old truck. Now he’s asking where he can buy them. I suggested he throw the ****ing spacer away and do it right this time. Mine isn’t perfectly level, but honestly the slight rake isn’t noticeable like before and I’m not going kill myself. The companies selling these spacers without correct UCA’s are doing their customers a disservice and are likely putting people in danger. I get the people installing them should know better and a lot of customers don’t know or don’t care, but it’s really not worth potentially trashing a $60k truck and almost killing someone over it.

Anyone else regretting going with the 3.0L Duramax? In all of my previous GM trucks I’ve had the 4.8, the 5.3, the 6.0, and 6.2 gassers and I thought I would try something different this time, especially since the duramax was reduced in price for ‘21. After driving it for 5k miles I’m having regrets. Sure the mpg’s are slightly better, nowhere near the advertised mpg’s though, but the overall power to me just isn’t there. When I go to pass someone at 65mph and put it to the floor, it reminds me of the seriously underpowered 4.8 I had in my 2008 Silverado. Just doggy and laggy and doesn’t seem to have the power to propel it forward quickly. The 4.8 had slightly more hp at 285hp but a disappointing 295lb.-ft torque. I hated everything about that engine. The duramax eventually gets me there but when I’m having to go around a semi I don’t need to be wasting time while my rubberband winds up. I understand it’s ‘only’ 277hp. I would like it if there was a chip that could get it to 300hp but then I’d be worried about the unintended wear and tear on all of the other components maybe not being able to withstand the added power over the long term. Looking back I really should have waited and found a 6.2 AT4 in the color I wanted.

that’s worthless.

Do 2021’s not leak?

yeah we have 600 cows and just calved out 60 first calf heifers. But that’s my work truck. This is my town/trip truck.

I’ve had my ‘21 AT4 for a couple thousand miles and the new truck smell is sadly already gone. what’s everyone’s favorite new car smell air freshener or spray thing or bag thing to keep the new new longer?

ordered

I'm betting there's a dealer in another state that will honor it and deliver the vehicle to you. Mine was delivered from another state from four hours away. Delivered to my door and drove my trade-in back. This dealership delivers all over the country, the delivery driver had just gotten back from Louisiana the earlier in the day. I get people hate California but denying someone a buying opportunity just because they live there isn't cool.

So I did fold my mirrors in for a good 100 miles across northeastern NM and I'll be damned, I think it did make a 1 to 1.5 mpg difference. I had a generous tailwind and was getting 29-30mpg on the 50 mile average! The entire trip 250 mile trip averaged 25 mpg which is the best so far. On the 25 mile average coming through the canyon I got 48.9mpg, I'll be trying for 50mpg next time lol

I had all intentions of going Trailboss. Until I sat in a Sierra AT4. Brought home the 21 AT4 with 10 speed. Also went with the duramax but the jury is still out for me on that. It is $1500 less than the 6.2 now though.

Mine were installed at the dealer. 21 Sierra 1500 AT4

What was the remedy to this? Just dirty or something else?

Mine was $354 and some change from a local shop. Bilsteins all around and Cognito UCA’s with alignment. I’m told that’s cheap.

Ahh ******. You’re correct. Forgot that step. JMHAUDBDIIENAOLANP No expertise implied or expressed

I was always taught you measure a tire’s size by making a mark on the tire and a mark on the ground, lined up. Pull the vehicle forward (or back) until the tire mark makes one complete rotation and then mark the ground again. Measure the distance between the two ground marks and that’s the tire size. JMHAIDBDIENDOP No expertise implied or expressed

I have the bilsteins set to the 1.1” and the AT4 is more level. Not perfectly level and still noticeably not level, but so much better than stock. the Cognito UCA’s fit using the stock 275/65r18 duratracs. I think a 285 tire just might barely fit. I really want to try a 285/70. If I have to do a little trimming or fitting of the fender well then that would be ok. Just don’t want them rubbing the UCA.

My dealer is 4 hours away. My mechanic is 5 minutes away. Warranty be damned. Also, shop local and all that jazz.