Career
He retired as the New Zealand national team"s all-time top try scorer, with 16. Since retirement McGahan has worked as a rugby league newspaper columnist and a football manager. He later moved to Sydney to play for Australian club Eastern suburbs from 1985.
In 1987 the Roosters captain was named the Dally M backrower of the year.
The following year McGahan was co-recipient of the Adidas Golden Boot Award with Peter Sterling. In his final season with the Roosters McGahan took over as captain-coach following the dismissal of Russell Fairfax.
He played in over 100 matches for the club from 1985 until his retirement at the end of the 1991 season. Following his retirement from the club, McGahn was a director of both East"s the leagues and football club
McGahan represented New Zealand in 53 tests.
He was the captain in 17 of those Test matches. He once scored 6 tries in a test match against Papua New Guinea. The award is given to the player judged to be the best international football player of the year.
That year he also served as caretaker coach of the Eastern Suburbs Roosters.
In 1995 he was one of the initial inductees of the NZRL"s Legends of League. McGahan went on to sports management roles in the United Kingdom and back home in New Zealand and successfully built his own management company, which he still runs today.
In 1999 he was the Auckland Warriors football manager. In 2006 McGahan coached the Waitemata rugby union club
The side made the Auckland Rugby Union grand final.
On 5 November 2007, McGahan and former All Black Doug Rollerson, appeared in the Auckland District Court on charges of alleged fraud. A small group used an elaborate scheme of invoices and accounts to defraud sports organisations out of charity money. The group was accused of supplying Touch New Zealand, the North Harbour Rugby Union and Team Harbour Limited with false invoices.
McGahan pleaded guilty and in May 2009 he was sentenced to 270 hours of community service.