Speedometer doesnt register until about 20 mph and when it decels to about 20 mph it falls flat. Also does not shift properly until speedometer comes online. Have replace shift solenoids, cleaned and or replaced wheel speed sensors and tail shaft sensor. I know cluster is bad because the other gauges are messing up too. If I replaced ip cluster will that resolve the shifting issue? Thanks for any help

 

Welcome from Florida. If you can solder, you can repair the cluster yourself. There was a problem with the stepper motors in GM cars from around 03 to 06. I used to have an 03 Trailblazer with a bad speedometer. I replaced the stepper motor for the speedometer and the other 5 gauges and the cluster worked great after that. I do not thin the shifting problem is related to the bad cluster. Unfortunately I also had the transmission go bad at just over 50,000 miles and had to have it rebuilt.