RPM moves speed goes till 80km. on 2005 Chevrolet Trailblazer

My car RPM moves but car can't pick up some time goes till 60
what is the problem

2 answers 1 comment
have some one scan trans sensors and sloenoids like aamco with there free diag
today I will go for scan let see! The mechanic replace Gear Oil and GearOil Filter
Sounds like trans.trouble.