The former Ireland Wolfhounds coach works alongside Gregor Townsend, Matt Taylor and Kenny Murray at Scotstoun to oversee the coaching of the forwards.
The former prop, who made over 100 appearances for Connacht from 2000 to 2006, has also played for Richmond and Stade Francais.
McFarland was appointed forwards coach at Connacht in 2006 and then assistant coach in 2010.
The Irish Province now regularly challenge for a top six place in the PRO12.
In 2007, McFarland linked up with Eric Elwood to guide the Ireland Under-20s to a grand slam of victories in the Six Nations Championship.
His international coaching experience extended to stints with the Emerging Ireland tours and the Ireland Wolfhounds in January of this year.