NHTSA Complaint #11675854 — 2018 CHEVROLET SILVERADO 1500

10 miles from home on [XXX] after Thanksgiving with my children sleeping at [XXX] in snowy cold weather, my engine began to fail. Power was limited on hills and the check engine light would come on and go back off when on flat or downhill. The next morning I took my truck to the dealer that I purchased it from where I was told the lifters had failed and I need a new engine. 1000 miles after I replaced my engine my transmission failed completely requiring a transmission replacement. Immediately upon picking up the vehicle and going down a long hill in the area, engine breaking turned on as expected but as the truck tried to slow itself, after 2 or 3 downshifts, the transmission began making a loud grinding sound and while still going close to 50 MPH, the speedometer showed 10-15 MPH and the tach dropped to idle. The transmission was decoupled from the motor. When gas was reapplied it seemed to make the connection again and resume normal driving. I called the dealership whose techs did not believe me and told me that I could 'turn off' the engine breaking feature. The situation continued to worsen each drive and it would do it more often. This was unacceptable and they finally had a tech ride with me to experience it and immediately agreed there was an issue and reordered another transmission. The third transmission did not fix the issue and was experienced immediately. They are now guessing how to fix the issue telling me I have to replace the transfer case out of my pocket with no diagnosis, not sure what is causing it and have not fixed the problem. Videos would not fit in upload due to size. Videos show speedometer failure. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)