My 2005 Avalanche changes gear hard after it's driving it

Question edited for clarity.
Question moved to model category.

It doesn't have one. Click this link, click on the Autozone link with the picture of one. One the site, add your year and engine, NONE comes up, it doesn't have one. There are no videos showing it for that model.

https://www.google.com/search?q=2005+Chevy+Avalanche.+idle+air+control+valve+location

AutoZone

https://www.autozone.com/engine-management/idle-air-control-valve

....

The 2005 Chevy Avalanche is available with different transmission and shift options, which can affect the number of transmission shift solenoids present.

However, generally, the 4-speed automatic transmission (4L60E) used in the 2005 Chevy Avalanche typically has a total of 7 transmission shift solenoids. These solenoids are used to control the activation and deactivation of the transmission's clutches and valves, allowing the vehicle to shift gears smoothly and seamlessly.

It's important to note that the number of transmission shift solenoids may vary depending on the year, model, and configuration of the Chevy Avalanche.
>

Chevy TH 700R4 and TH 4R200 overdrive automatic transmissions have this problem at times. 3rd gear is as high as it will go when in "limp home" mode. This is so you can get home but not hurt the trans any farther. Reason being, you're overdrive clutch pack is burned out and needs a rebuild. Rebuild is cheaper than new replacement.

My first guess would be a restriction in the radiator or a faulty bearing in the fan motor.

I would replace both universal joints on the drive shaft.

Your gauge problem probably stems from failing speedometer drive motors, very common on Avalanches and most GMs.

I specialize in Avalanche speedometer repair, have a look around my site at www.DrSpeedometer.com

ON SOME GM'S IF YOU CHANGE THE TRANNY FILTER IT WILL FIX IT, I WOULD TRY THIS FIRST BEFORE I TAKE IT A SHOP

i had the same problem, its the torque converter. I took my 05 c/a in because i was having shifting problem, the long and short of it is there is a breather on the tranmission that sucks in water from the road. the water and the atf dont mix. the dealer put in a torque converter and changed the fluid and installed a redesigned transmission breather.

Hello;
Are you getting the check engine light? If so the electronics may have gone out. You may not need a rebuild but you won't know till you pull the oil pan on the transmission and inspect the contents. You may also have lost the neutral safety switch. It is mounted on the drivers side of the transmission. Check those out first and let me know what codes you get.
For Ponchoboy; the clunking and hissing you hear are teminal root causes. Drop the oil pan and if it has a lot of filings and metal it is time for a rebuild.
Hope this helps; Rate me highly;
Rich
RPM Northwest