Troybilt Mustang 42" Right Arm Sticking

I have a 2015 troybilt mustang zero turn 42". The right arm is sticking and realized the spring on the very bottom under the machine is missing.. I can't find the spring on parts manual.. Anyone possibly know the part number im after? There is a matching one on the other side of the mower..

https://www.troybilt.com/equipment/...urlRequestType=Base&langId=-1&catalogId=14102

scroll down page for parts, your model number is 17BDCACS066