Z45

Having owned 4wd vehicle since the 1970s I find there are varying opinions on how to use 4wd, every owner is an expert in their minds. IMO, 4LO is the appropriate gear and what I would use, You have to feather the gas to avoid spinning tires and the lower the gear the better chance. But like I said you will find those that think their method is best. I live near a boat launch. Yesterday there was a new Ford Maverick pulling out a pontoon boat almost 2x its size, they had no problems and they don't have a LO range. True story. One winter day not long ago I was coming out of small town post office and there was a F150 4wd parked in front and was stuck foot deep snow ruts. I knew the lady so I asked her to put it in 4wd (wondering why in the middle of a 2-day snow storm she wasn't). Her reply surprised me, "my husband" (the expert) told me not use that because it uses too much gas. She finally got unstuck spinning in 2wd which likely used more gas than not.

Some tires have more tread depth thus a different circumference. Tread depth will vary by type, brand, and model. https://www.tirereview.com/science-behind-tread-depth-passenger-tires/

Dirt settles in the door drain holes and traps water....lower corners of inside door skin.

These codes don't automatically clear if you fix the problem?

I have the GMC accessory (REV) cover installed by dealer. Ordered with the truck. They did a very good install job, can't find a single issue. Some water gets in around the tailgate but no where else. You can see daylight around the tailgate but that's not the covers fault. Installation is means everything. Guys at my dealer were seasoned pros, not inexperienced here today good tomorrow types, like many dealers employ for these jobs. I don't mind paying for a professional job.

Tires of different brands may have different circumferences (or radius) even if they are the same size.

Problems are blown way out of proportion due to the internet. The same experiences get repeated over and over again till it sounds like a real problem. There is NOT an vehicle out there that does not have some issues. Building 100's of 1,000's of vehicles with 1,000's of parts from various suppliers all over the whole, some quality control issues are going to make it through the process. The internet is full of misinformation often designed to change readers opinions. I have had 2 trouble free years with my 2024 Sierra, don't tow anything heavier than a 2026 Ranger NorthStar and mostly a around town. I personally know 3 others with same engine and no issues, 2 are LM2 version and 1 is the LZO, all three happen to be GMC's. All of these owners are older persons (40+) so that may have a lot to do with it. No modifications, no big tires, suspension hacks etc, just normal use. One who has a 2021 LM2 has over 100,000 miles and travels estimating projects for the electrical contracting company.

Was back in early June 7th as I recall

Don't know if all will be able to see this. Valvoline Cuts Dexos Claim from Synthetic Oils https://www.lubesngreases.com/lubereport-americas/11_27/valvoline-cuts-dexos-claim-from-synthetic-oils/

dexos began as an effort for GM to control the oil change market because the Quick Lube Industry was eating into dealer service department profits big time. So they attempted to get other oem’s to develop standards as well and that would make it hard for Quick Lubes to compete because all the oems would be different. GM faced lot of industry push-back, mostly the quick-lube industry and they went to licenses. Still GM it making a ton of money (est'd 30-40 million in 2025) off the license structure as they charge a hefty fee to get oil tested then require a royalty on ALL gallons sold applicable to GM vehicles.

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.

https://www.gmc.com/future-vehicles/2027-next-generation-sierra-1500?evar36=B2000016304.OP_EML_GMC_OW-2_DRE_CA_REV_T1-2_REV_20260625..V7_-1305730338&evar110=M_IMG_SIERRA_2&hid=E3F70EF51E5951E3EC37EF6993D5EDA5B6D0343007DE7D3E13A28BC2984F3FC59

Kind of hard to answer a ? like this without a part number and brand of parts?

Lake Speed is drumming up business for his company just by being in the spot-light so he has a vested interest in stoking the 0W-20 fire. IMO

1Based on independent testing of OE 0W-20 in the Peugeot TU3M Wear Test as required by the dexos1 Gen 2 specification.

Makes me wonder what motivates these so-called experts (in their own minds) to make all these videos against 0W-20 Oils? They will never change OEM's from recommending it. Got to be making $$ somewhere from these crusades?

Friend works for a technical research university that has winter driving school and GM had donated a Sierra Denali to the school. They had to eliminate the AWD system so they had to replace the transfer case and lots of other parts. The AWD uses a Borg-Warner TC. I recall him saying it was a pita job but they had engineers that could do the job. Btw, the Denali did not have a VIN so it have to destroy the vehicle when they were done with it. GM's way of making sure the vehicle did not end in the wrong hands.

https://www.chevrolet.com/ownercenter/recalls 2020 GMC Sierra LD Crew SLT/Elevation-T1 VIN: 3GTP8DET0LG444836 Recalls Recalls and/or programs for your vehicle in which repairs have not been completed are listed below. GM provides information on this website for recalls announced on or after August 20, 1999. This information is available for vehicle in which repairs have not been completed. No Incomplete Recalls NOTE - Not all repair shop/Dealers reports to Carfax

Had brakes put on a 1999 Sierra once at local small town GMC shop. The new pads were squealing a lot so I went back and complained. Found out parts guy (slip of the tongue) they installed local parts store junk. Never told me that and when I checked my bill it listed GM part numbers and what I assumed was GM prices. I think they realized it was a problem because they had order the GM rotors and pads and never changed me a dime. New brakes did no squeal. btw-That dealer is out of business today.

Dealer oil changes are a marketing ploy. You hang out in the showrooms, wander the lots and look at the new trucks/autos all the while the service dept. looks for something they can up-sell to the customer. GM dealers call it a multi-point inspection. They have a vested interest in having you come back again and again and again. Think about it, how many want you to keep driving your vehicle? You are the only one; the dealers want to sell you a new truck and every time you are there, they get another chance.

I would seriously look at the tire/wheel assembly and associated parts that hit the pot-hole. Take it to the GM dealer, warranty might get involved.

Some truck configurations are no longer available for MY26 ordering: Chevrolet Silverado LD Double Cab — Closed GMC Sierra LD Double Cab — Closed Both double cab configurations will be unavailable for approximately 13 months due to plant retooling. Fleets requiring these models will need to consider alternative configurations or model strategies. Cut-Off: March 27, 2026 Brand Model Important Note Cadillac Lyriq EV model Cadillac CT4 Sedan Chevrolet Silverado LD Regular Cab 8–9 month plant retooling gap expected GMC Sierra LD Regular Cab 8–9 month plant retooling gap expected

I have owned many GM 4wd vehicles dating back to the 1980's and driven all the big 3 brands at work (GPS Survey team). Granted I live in upper Michigan where its winter (300+ inches of snowfall this past winter) from Nov-April (+-) but other than having it in AUTO 4wd then, I never excise it when I don't need it. Never an 4wd issue ever. Btw, according to a fiend who is GM tech, 99% of 4wd issues he encounters are attributed to oversize tires. Now if you are one who has a 4wd just for a status symbol (many do) and really never use it then it might be a good idea to do that occasionally just to make sure you know how to use it. LOL.

The problem for Gr III Base oils ---------------->https://www.gasworld.com/story/shell-expects-year-long-outage-at-damaged-qatar-lng-train/2251101.article/