Hensley began racing at the age of eighteen, racing in various short tracks in Virginia and North Carolina. In 1982, he moved to the newly-formed Busch Grand National Series, competing in the No. 63 for his family-owned team. In his first season of competition, he ran ten races, and had five top-ten finishes. His abbreviated schedule landed him twentieth in points. The following season, he ran twenty-eight of the schedule thirty-five races, and had nine top-ten finishes, and improved to tenth in standings. He had two less top-tens in 1984, but had a career-best eighth-place finish in points. After he dropped to three top-tens in 1985, in the No. 2 Flute's Sheetmetal car, he retired and became the crew chief for his family's No. 63 car. He worked with Jimmy Hensley, Larry Pollard, and Mike Swaim over the next three years before Chuck Bown became the new driver of the 63 in 1989. They won the championship together in 1990, earning Hensley Mechanic of the Year honors. They continued to work together until the 1994 season, when Bown left and was replaced by his brother Jim. Hensley continued working for the team until it was sold in 2001. Following the sale, he worked for Arrington Manufacturers for three years before returning to the track when he was hired by Bill Davis Racing in 2004 to serve as the crew chief for Bill Lester's No. 22 truck. The following season, he was reassigned to the No. 5 of Mike Skinner, where he stayed for two and a half seasons. He and Skinner won eight races and finished second in points during the 2007 season. In June 2008, he left BDR for personal reasons, before he was hired at Hamilton Racing. Hensley then moved to Red Horse Racing for 2009 and 2010 to work with Timothy Peters. The duo won in both years with victories at Martinsville and Daytona. Hensley left RHR after 2010 to work for Kevin Harvick Incorporated. Though he initially served as Ron Hornaday's crew chief, he moved to crew chief for Nelson Piquet, Jr. and the No. 8 truck, before joining Joe Denette Motorsports for the final race of the season. In 2012 he started the year with JDM, reunited with Hornaday, before moving to Turner Scott Motorsports to crew chief for Miguel Paludo halfway through the season, a role he reprised in 2013. At the start of the 2014 season, Hensley moved to NTS Motorsports as crew chief for the team's No. 20 truck.
