2001 ZR2 tracker shift solenoid

My tracker is starting to hesitate shifting out of 1st . Going to try and change trans fluid and filter also want to install a new shift solenoid to see if this will help. The problem I check online and can not find a shift solenoid for a 2001 Chevy tracker ZR2 with a 03-72lE 4 speed auto. Help.... Thanks genehb