Jon Gosselin -- who has been dropped from his TLC show, Jon and Kate Plus 8 -- wants to put his club-hopping reputation to rest.

On Saturday, the reality father of eight, 32, participated in the "Walk Now for Autism Speaks" fundraiser in Philadelphia.

He says he and estranged wife Kate first got involved in autism causes nearly a decade ago.

"Kate and I used to babysit an autistic child when we were first married, so I realized firsthand -- albeit on a smaller scale -- the work that goes into creating a safe and happy life for a child with autism," Jon tells exclusively. "The experience had a great impact on me."

Another reason volunteering is so important?

"When my youngest children were born, tons of volunteers helped us with food [and] clothing," he tells Us. "Without their aid, we never would have been able to support our family and for that, Kate and I have always been grateful."

Jon adds that while he and Kate, 34, have "made it a point to focus on our family," they also want to help other families so they "can benefit the way that we have."

He hopes his volunteer work will inspire his eight children -- 8-year-old twins Mady and Cara and 5-year-old sextuplets Aaden, Joel, Collin, Hannah, Leah and Alexis.

"Actions speak louder than words," Jon tells Us. "I believe that participating in charitable endeavors sets a good example for our kids."