In 1978, he started working at Wayne Charvel's guitar repair shop in Covina, California (while using a PO Box in neighboring San Dimas).
Although Jackson and Charvel Guitars became popular with the rise of hard rock and heavy metal music in that era, Grover Jackson sold the Jackson/Charvel brand to the Japanese manufacturer IMC (International Music Corporation) of Fort Worth, Texas, in 1989, and eventually left the company in 1990.
During this time he designed and supervised the "Chicago MG" and "Mercury" guitar and "Bantam" bass series.
He also worked with Dimebag Darrell to design and build his signature guitars (Washburn Dime series).
His partner in this venture was former Fender Senior Vice President Jon Gold.
In the 1990s, many models were produced as Japanese market exclusives under "Grover Jackson" brand name.