Sierra Dan

It took 5 years for the 6112's to actually be released and available for the '14-'18 K2 GM trucks.

This was my guess also. The old greasing of the steering shaft boot........

Was it the "Tenneco" branded Rancho?

Check for metal shavings in your oil. Failed Vacuum pumps on K2 trucks led to some issues of metal entering the engine.

Dale, You might want to post this in the correct thread for your truck. This is the Future truck section. Good luck!

Another Russian Hacker.....

How did a Russian Hacker gain access to our Forums ?

The Covid outbreak has no doubt delayed auto production. Colorado is getting long in the tooth.

Mine lasted around 30k miles but looked 20 years old on the outside. I called them my pogo sticks and happily switched to Bilstein 5100s.

The Early years of K2 GM platform trucks had this same issue. Dealer attempted fix consisted of plastic clips that kept the seat bracket from shifting to the side causing the clunk. My fix was a rubber hose and clamp! Sounds like the T1 trucks are plagued by some of the same problems as the K2s Along with creaky rear leaf springs and other. Here is a 70 page thread on the seat popping noise issue. https://www.gm-trucks.com/forums/topic/154219-seat-movement-issues/page/70/#comments

Shut down the Wet Markets and bring back manufacturing to the homeland. Just my humble opinion.

+2 on this. The K2 trucks have this warm up tick also.

Don't forget about the new rear Independent Suspension as well. Also coming to Yukon and Tahoe

Range type devices only add a band aid to the potential problems and are not a true "delete". Here is a great site explaining why a delete kit works better than tuning afm out electronically. Just my 2 cents. http://bdturnkeyengines.com/afm-dod-info

There is a special coverage warranty on the Vacuum Pump. For 6 years or 72k miles as long as the dealer confirms that the Pump as bad.