Wd-40 is a water displacer agent. Nylon gains its flexibility from water intake. It shouldnt make plastic more flexible. I bet leaving ur arms on cooling down boiled water would be a lot better than wd40. But thats just meI installed the oil soaked EXB a-arms today and beat the truck to death and nothing broke. I would like to thank all of you for your sound advice and help resolving this issue. I haven't had this much fun beating my truck in a long time.