2003 avalanche parts re-call

dealer said there was a re-call on the guage cluster for my 03 avalanche, but because my vehicle has more that 70k miles, its not covered and i have to pay out of pocket. also, my break/running light does not work on the rear passenger side. transmission slips, could changing my fluid fix that, or is there a bigger problem. id appreciate some info and guidence. thanks

Welcome to AF.

Is your cluster not working right?
What is it doing or not doing.

On brake and tail light I would check buld and wiring and bulb sockets.
Ant add on trailer plug in?

Is Transmission slipping in all gears?
Have you checked the fluid level when hot in park?
Is fluid dirty or burnt?
If more than 70K on transmission service it is well past time to change transmission filter and see what is in the bottom of transmission pan.
How many miles on it now and when was last transmission service?
But do not get carried away on one of them transmission flush add any oil juiffie lube jobs.
Just pan drop and filter change with dexron fluid will do it.

Do you have any engine or transmission codes or lights on?