Z45

To the original post on warranty concerns, this from the FTC; https://www.ftc.gov/news-events/press-releases/2018/04/ftc-staff-warns-companies-it-illegal-condition-warranty-coverage

What RPO sticker are you taking about? The window sticker or glove box/door jamb sticker? Either way, if its not the current model year it may not be available but the only source (if available) would be a dealer, preferably the selling dealer. You can try to contact; [email protected] with a VIN and they will send a build out pdf file with all options but it won't resemble the stickers that came with the vehicle.

Somewhere along the way the dealer washed it.

When this occurred to my Sierra, it was collapsed lifter/bent pushrod. That's the only warning light I saw along with stumbling engine...

Micro scratches in the paint are inevitable and the darker the color, the more pronounced it will be. I own a black truck and I yet to see one that did not show scratches. Its impossible to touch the paint washing it and not do this. If you think your dark colored paint is not, look at it from different angles and in different sunlight. I have even seen it on white paint.

from GM service info.... Chatter is essentially the build-up and release of energy between the differential clutch packs in a limited slip differential during operation. This phenomenon often occurs when torque is transferred between the clutches or when rotational speeds change. During the stick-slip phase, energy is built up to a point where contact between the clutch plates change between static friction (stick) and dynamic friction (slip), resulting in noticeable vibrations. It is this vibration that causes an audible chatter or ratcheting to be heard within the differential. While certainly an annoying characteristic, there is typically no mechanical damage occurring to the differential. It is most often noticed in parking lots or slow driving while turning where the outside wheel turns faster than the inside wheel. In an effort to control this chatter, friction modifiers are often used. These additives result in a smoother transition between the two states of friction: static and dynamic. Static friction occurs when the clutches physically lock together, while dynamic friction occurs as the clutches are slipping, ergo Limited Slip Differential.

Its NOT a limited slip differential... ¨ Optional Equipment (G80 Order Code) on all GM two-wheel and four-wheel drive light trucks and sport utilities. Benefits ¨ Improved traction differentiates the vehicle relative to other rear wheel and four-wheel drive vehicles on the market. ¨ Maintenance free; requires no lube additives. ¨ Enhanced towing and off-road performance. ¨ Patented carbon friction disc technology enhances performance and durability while reducing warranty claims. Principles of Operation ¨ Wheel speed difference (left to right) in excess of 100 RPM will cause a flyweight mechanism to open and catch a latching bracket. ¨ The stopped flyweight will trigger a self-energizing clutch system, which results in the cam plate ramping against a side gear. ¨ Ramping increases until both axles turn at the same speed (full lock), which prevents further wheel slip. ¨ At speeds above 20MPH, the latching bracket swings away from the governor and prevents lockup from occurring. Technical Specifications ¨ Automatic locking takes place within a fraction of a second, so smoothly that it is unnoticed by the average driver. ¨ Unlocking occurs automatically, once the need for improved traction is gone, and is unnoticeable to the average driver. ¨ Compatible with anti-lock brake systems.

Dealers only.....its proprietary.

Oil pressure is directly related to resistance to oil flow. Because of the lower resistance to flow that synthetics offer, the oil pressure will generally be reduced as well. Lower resistance to flow also means less friction and potentially better power or efficiency.

Keep in mind that some noise is a normal characteristic of leaf spring suspensions when traveling over rough roads or bumps.

I know you have a K&N but this is why it won't work. Its screwing up your system.... Here are why such add-ons are not compatible.

When mine was in for warranty work last week the used; 19419227

Mine failed at 11.400 miles and was on cruise at 55mph. Heard a strange noise and at first I thought I rode over something and tire was going flat but air pressure was holding. Came to a stop sign 1 mile later and truck was stumbling. GM dealer was within 1/2 mile so I pushed on and they took it in right away and were 99% sure what the problem was. They had all the parts in stock. Drivers side replaced, was only w/o for about 1 day.

Mine was the #5 cylinder that collapsed at 11,440 miles 6.2L. I was only a mile from dealer when the engine started making noise and running rough so I limped in. They took it in right away and showed me the bent pushrod an 2 hrs hater. Mechanic who started it up, knew right away what it was. Said they seen a few but mine had more miles then most. Curious if its always the same cylinder? Never thought to ask dealer. Replaced all lifers on same side of engine (drivers side 3rd one from front is #5. PS, in at 3pm Weds, had truck back at 10am Friday. They had parts in stock so that tells you a lot. They don't stock parts like this unless they use them frequently. At least this dealer has savvy parts people to anticipate the need.

Frequency of oil changes is the key to success in pushing related products and services for the OEM dealer. A few free oil changes can go a long way toward increasing the amount of money a customer will spend at the dealer during the ownership of the vehicle. In other words, you are money in the bank.

Life is to short to worry about things you have no control over.

2021 Sierra Denali 6.2L 11,600 miles (11 months). Driving down road yesterday at 55 on cruise and it started jerking and making noise. Limped about 1 mile to GM dealer and they were able to take it in right away. 2 hrs later they were showing me a bent push rod and putting me in a loaner. Shock, they had the parts in stock and I should have it back today.

Not to mention camera's, if you leave your house you're on someones camera.

Got a pic of it? I use to have that in one of my trucks and have some spare parts...

Commodity oils such as Rotella are made to a price point. There are also limited to using base oils and additives only they produce in house. Their synthetic base oil (GTL) are only produced in one place, Qatar. AMSOIL is made with the best components money can buy without regard to cost in the USA (Superior, Wis since 1972), that's their reason for being, be the best money can buy. Commodity Oil -- Oil that is of equal value to a consumer no matter what company produces and markets it, and as such, is available at any discount with little differentiation among brands.

I just noticed 2 local GM dealers got an influx of trucks recently (over 20 between them, 21 and 22 models) and they all have DFM. What they don't have is Stop/Start.

AMSOIL sells a tool for that BUT don't know if bottles other than theirs fit and it comes with 10 ft of hose, no bottle w/tool, that comes with the kits they sell. And no, they do not do the testing, it done by Polaris labs, an independent lab..

I would be asking them to put it back to stock (no charge). Its apparent the parts or the installation are not working. While they might be good guys in your opinion, they can't fix the problem apparently and that would lead me to question their skill.

Go for it. I While not a diesel owner myself I have used AMSOIL exclusively since 1978. No better oil on the market IMO.

Are the lights stock or LED?