Lee White stepped down Tuesday as president of Toyota Racing Development and Toyota Motor Sales.
White will officially retire at the end of the year, but remain with Toyota until then as a special advisor until then. TRD said he is stepping down immediately to tend to family health care needs.
''I have been planning and working toward retirement at the end of this race season in December,'' White said. ''I have been offered and accepted an opportunity to perform a reduced amount of duties from my home office. This generous arrangement afforded to us by the company will allow me to attend to personal family priorities.''
White joined Toyota in 1997 and took over the top job following Jim Aust's retirement in July, 2008. He was responsible for all TRD North American motorsports activities in NASCAR, USAC, NHRA, Grand-Am and off-road competitions.
The announcement comes as TRD is struggling with durability in its engines, beginning with the Daytona 500 when Matt Kenseth and Kyle Busch suffered engine failures within minutes of each other. Most recently, Kenseth and Martin Truex Jr. both suffered engine failures in Sunday's race at Dover.
Although Toyota drivers have five wins this season in the Sprint Cup Series and eight poles, TRD engines have failed six times.
White also took responsibility for a quality control issue at TRD that led to a heavy part in Kenseth's race-winning engine at Kansas in April. NASCAR levied huge penalties against Kenseth and Joe Gibbs Racing for the illegal part, but an appeals board later reduced the sanctions while upping TRD's penalty.
TRD on Tuesday made no mention of the engine or parts woes in announcing White's decision.
White's responsibilities included engine development, manufacturing, chassis design and development, team and manufacturer relationships, manufacturer and sanctioning body relations as well as engineering support for Toyota teams. He began his career in racing with LeeCo Engineering as an owner, driver and engineer. He was also manager and engineer for Read Racing Engines, and a team manager and engineer for Herman Miller Porsche Racing. He was a general manager and engineer for Roush Racing, Rocketsports Racing and Newman Haas Racing.
White was with teams that won approximately 1,000 races and 250 championships.
''Lee has contributed enormously to Toyota Motorsports in his 15 years with TRD. His leadership has resulted in victories and championships in a broad spectrum of racing series,'' said Toyota Group Vice President and General Manager Bill Fay. ''He's had an impressive career and his day-to-day leadership will be missed.''