2018GMC

Fixed? How many miles? Why did it bend pushrod? Mistimed AFM event?

Fixed? How many miles? Why did it bend pushrod? Mistimed AFM?

Well I'm out of ideas. I still get a service stabilitrack occasionally, along with B127E especially if I turn truck off and then restart after a few minutes (like when in a long line at drive thru). I also get a random service safety restraint system, airbag light, along with U0140 Lost communication with Body control module only if i leave a door open when truck warming up for several minutes. Shut truck of and restart, no message and airbag light goes off, all seems normal after that.

I still randomly get a service stabilitrack or service safety restraint system once in a few months. I used to get them fairly often. Replaced positive and negative battery cables, cleaned ground under passenger front fender liner and driver seat on frame rail. More info here: Guessing its a loose connection on harness somewhere...

Update: I got the service stabilitrack error randomly on startup a few months after Dealer replaced negative cable and bumper to bumper warranty ended. Occasional codes of B127E, B127B, B1325, U0121, C0800, U0073 Replaced short positive cable from battery to junction box. All connections were tight. Cleaned ground on outside frame rail under drivers seat. It's been 2 months and no random codes or stabilitrack. Next thing will be to replace battery if codes come back.

Voltage changing while driving is normal as stated by others. If you have starting issues or odd messages on screen after starting (service stabillitrack, low battery, service restraint system) Check the resistance in the battery cables. I had my dealer do this before warranty was up and my negative cable tested bad (high resistance). They replaced that and no more random messages after startup. https://static.nhtsa.gov/odi/tsbs/2019/MC-10168185-9999.pdf

Thanks that worked!

Yes the new version has issues. I have the GMC app (same thing) The press and hold keep holding is annoying. I can’t get Face ID to work. Always asks for my pin.

High resistance in battery cables can cause low battery warnings service stabilitrack, etc. dealership replaced my negative cable after it tested bad. No more service stabiltrack service safety restraint system. I never had issues with power steering going out though.

Not an AT4 but my 2018 crew cab 6.6’ 4wd SLT (sunroof, bucket seats) 6.2L Max tow payload is 1900lbs. Love the looks of the AT4 but with softer springs for better off-road ride payload is reduced. You could always add sumo springs, add a leaf or air bags if it squats too much when loaded or towing.

Damn! Guessing you are out of 3 yr bumper to bumper but still covers under 60k 5yr powertrain warranty?

Damn that sucks. Maybe it’s not fully latching or only latching one side? Dealer can scan for codes if it’s electrical issue.

Sumo springs are another option to reduce sag and sway. Available for truck and trailer https://www.amazon.com/s?k=sumo+spring+Chevy&i=automotive&ref=nb_sb_noss_1

2018 crew cab standard bed 6’6” 6.2L max tow 4x4 SLT sunroof etc. I’m 170lbs, full tank, 80lb Tonneau cover 6000lb - 170 - 80 = 5750 lbs curb weight 3520 Front Axle 2480 Rear Axle

Blackbear CAI comparison Dyno test results http://blackbearperformance.com/IntakeTestResults_2016.asp

2007 both models were sold. 2007 classic GMT800 and 2007 new GMT900. Of course your same body style 2007 classic parts will swap. The gmt900 rear bumper may fit as well since GM used nearly the same HD frame until the 2011 HD refresh. You CAN bolt up rims from up to a 2010 to your 2006 GMT800 HD. You can also use newer 2011 - 2021 current HD wheels if you buy hub bolt pattern adapters.

Just wouldn’t start one day? My 3yr / 36 warranty just expired. I was hopeful for a free batt as I saw the occasional service stabilitrack and low battery alerts but dealer just replaced negative battery cable as it had high resistance.

Amazon’s parts lookup guide leaves a lot to be desired. This is the correct battery, if you search reviews for Sierra or Silverado they state it fits.

My 2018 stock battery (prob 2017 manufactured) is “ok” but I can only get 30 min of radio at 70% volume before I get the low battery start truck warning. Stock bose radio but aftermarket 10” sub with 300w amp. only way to listen to radio without it turning off after a few mins is key on correct? When camping, tailgating, etc

Amazon has great deal on Acdelco professional AGM battery 94ragm https://www.amazon.com/ACDelco-94RAGM-Professional-Automotive-Battery/dp/B006N91C2M Batteries plus website prices are much higher vs the previous post 189 / 269 for me https://www.batteriesplus.com/search?q=Sli94

Along with: New interior Super cruise offered only on Denali trim.

I hear you on the thin, brittle, fragile paint. I have some marks on the rocker below the door as well. This is where the older generation of trucks had a better design IMHO. The door covered the side of the rocker. I know the K2 and T1 trucks are triple sealed doors but we have a 2013 GMT900 in the family and that truck is just as quiet as my 2018.

Firm up the truck. Air tires to max psi or at least the rear. A stiffer mono tube shock like bilsteins Sumo springs, Air bags, or helper leaf spring If you need new tires get load range E or LT light truck tire which has a much stiffer sidewall than the tires that came with truck. I specifically sought out the max tow NHT package. My loaded SLT 4x4 crew 6’6” bed truck has a payload of 1900 lbs & 11700 towing. it would be higher if it was a lower trim, no sunroof, less weight etc. FYI I’d never tow near max as that’s double the weight of the truck, get a trailer that big and heavy in some wind or swaying and you could be in for a crash. what’s different vs a non max tow? Extra leaf spring in rear spring pack. Larger ring gear in rear differential. Lower gears 3:42 vs 3:23 with 8 speed trans. FYI stock shocks on my truck were very bouncy, a quick reaction of steering input would make truck dive and bob like a ship on the ocean. I installed bilstein 5100 shocks all around which stiffened up the truck and it is much more controlled now. What’s your rated payload and towing? How much over? Can you put more gear in the trailer to relieve payload in the truck? While not overloading trailer payload. Of course if it’s a lot or you are not comfortable then don’t do it.