Auto Transmission Fluid

[tntkenny0927]

Hi again my 90 leggy L auto has about 240k my first gear is struggling to change it only happens on 1st gear runs over 4k rpm maybe redline gotta let off the gas for it to shift. i already did a complete transmission flush with filter change about a year ago i know subies run forever i run liqui moly 10w 40 for the engine and was wondering if there is something as strong for the transmission its our only vehicle and a got another baby on the way thanks for any advice god bless...