727 no reverse

I dropped the pan and the actuator piece had fallen out again. The servo piston is cracked, would this cause the actuator to fall out? Where is the best place to find a new piston, none of the local parts houses have it. What is the correct way for the actuator to go in since its rectangular?

Yeah it probably had a bunch of slop in it with the cracked piston so it let the strut fall out. If I remember right the strut will only fit one direction. The sonnax piston MadDart posted the link to works good or if you want a super duty piston contact Mr. RandyJ over on Moparts. He makes a 1 piece billet servo that is about indestructible. Cost about $75 if I remember right. Pricey but a fantastic piece.