CHAPEL HILL — Three years ago, Sylvester Williams was working on an assembly line at the Modine Manufacturing Company, molding lids and connecting parts to make radiators for 18-wheelers and other big trucks.

"All you could hear was machinery; all you could do was think," he remembered recently. "... And all I could think was, 'I don't want to do this for the next 30, 40 years of my life.'

"But never, back then, could I have ever imagined being here."

"Here" is North Carolina, 950 miles east but light-years from the $12-an-hour job in Jefferson City, Mo., that also included sweeping floors. "Here" is Kenan Stadium, where the 6-foot-3, 315-pound junior college transfer is slated to start at tackle on the Tar Heels' veteran defensive line.

It's quite a change from working on a production line - especially for an athlete who has played football for only three years.

"His story is unique," Tar Heels defensive coordinator Art Kaufman said. "But if you know Sylvester Williams and know where he comes from, then none of it really surprises you because that's what he's all about. He commits, and he's going to put all of his energy into what he commits to."

Early on in his teenage years, though, Williams admits he wasn't committed to the right things.

As a sophomore at Jefferson City High, he rebelled against almost everything - including education and his dad, who was suffering from high blood pressure and other health problems.

"He always tried to influence me to do the right thing, but at that time, I was in my own mindset," Williams said. His dad, also named Sylvester, grew so frustrated with his son's lack of attendance that he had the police escort him to school one day - although the teenager eventually ended up getting kicked out that year, anyway, because he'd skipped too many days.

"That was sort of my wake-up call," he said. "That's when I realized I had to start changing my focus."

When Williams returned to high school for his junior year, he attended classes and worked on improving his grades. Eventually, he was approached by a coach on the new football staff, wondering why he wasn't trying out for the team.

"Basketball was always my thing - I was a power forward," Williams said. "But I thought I'd give it a try."

He played on the defensive line his senior season, with decent success, but never saw a future in football - or in college.

That is, until he was working on the line at Modine after graduation, pondering whether he had any other options besides a job that topped out at $17.50 an hour (with a 20-cent bonus if you worked nights).

"I never really had a sense of the size of college football players; I just figured I was too small," Williams said. "But I was watching college games on Saturdays and I started noticing the stuff on the bottom of the screen ... and it would say (these guys) are 6-3, 220, or 6-2, 6-1, and I thought, 'Man, that's about the same height as me,' and it just started clicking in my mind that maybe I could play this sport."

That thought solidified when Andre Salmon, a teacher and coach at Jefferson City who become a mentor for Williams, took him to a Kansas State football game.

"On the ride back, he looked at me and said, 'I want to go to college, and I think football could help me do that,' " Salmon said. "I told him it wasn't going to be easy, but with determination and hard work, he could do it."

With Salmon's help, Williams contacted coaches at Coffeyville Community College in Kansas. But with only one year of playing experience and little film to show off, "it got to the point where the coaches just weren't returning my calls," Williams said.

Undeterred, he enrolled in classes in January, 2009. He hit the weight room and the books, and walked onto the team. If doubts crept in, he called Salmon, then worked harder.

"I had an OK spring, and when I went home during the summer, I worked out every day with some guys, learning the technique of the game and learning more about football," Williams said. "... I had a real good fall camp, and I ended up making the team. That was kind of my building point."

And he kept building. Division I recruiters started noticing his strength, his athleticism.

"His ability was big," Kaufman said, "but his work ethic was even bigger."

By his second season at Coffeyville in 2010 - when he recorded 52 tackles, 12.5 tackles for loss, blocked five kicks and was an honorable-mention All-America - Williams was taking official visits to Southern California, Mississippi, Oklahoma State and North Carolina.

He ultimately chose the Tar Heels, he said, "because they have so many great players on the defensive side of the ball, it just felt like a family. It just felt like the right place for me."

Despite being the new guy in town, Williams wasted no time finding his place in the family.

One Saturday last February, senior defensive tackle Tydreke Powell was worried, at first, when he received an 8 a.m. call from his new line-mate. Then he smiled when he realized Williams wanted a workout buddy in the weight room.

"He said, 'Let's get better, let's go to work. We can't be the best defensive linemen in the country if we're not working,' " Powell said. "And I knew then that this guy was something special."

Kaufman said Williams' biggest strengths are his power, quickness and work ethic. The latter might be the most important, what with only two years of eligibility remaining.

"He's got a lot to learn, but he's like a sponge - he absorbs everything that he's coached and that's in front of him," Kaufman said. During his six months in the radiator factory, Williams said he never could have imagined competing in front of 60,000-plus crowds on Saturdays - with a possibility, perhaps, of playing on Sundays someday.

"I never really thought that I would be as good in football as I am now, but I thought that football would give me the opportunity to earn a degree," he said. "... When I sit back and think about what I've (accomplished) and what's ahead, I just feel blessed. And excited."

robbi.pickeral@newsobserver.com or 919-829-8944.