Constituted as 1st Battalion, 6th Field Artillery January 1907, although some elements date from the Civil War (twelve campaign credits). Served as an element of 1st Division in France during World War I (eight campaign credits and two awards of the French Croix de Guerre with Palm; entitled to French Fourragere in the colors of the French Croix de Guerre). Relieved from 1st Division and assigned to 8th Division June 1940. Relieved from 8th Division July 1940. Reorganized and redesignated 6th Field Artillery Battalion January 1941. Overeas July 1942. Stationed at Fiji and assigned to 37th Infantry Division 8 August 1942. Moved to New Hebrides March 1943. Moved to Guadalcanal 3 November 1943. Landed at Bougainville 13 November 1943; participated in Northern Solomons Campaign (capture and occupation of Bougainville). Participated in landings at Luzon, Philippines 9 January 1945. Returned to the United States December 1945. Inactivated at Camps Anza and Stoneman, California 13 to 18 December 1945. Relieved from 37th Infantry Division and redesignated 6th Armored Field Artillery Battalion July 1946. Activated at Fort Sill, Oklahoma 1 August 1946. Inactivated at Fort Sill 25 June 1958. Consolidated with 6th Artillery, a parent regiment under Combat Arms Regimental System (CARS) 1 September 1963. Elements served in Vietnam with II Field Force, Vietnam (FFV), 1st Infantry Division and 12th Artillery Group and with 1st Infantry Division in Southwest Asia (Desert Shield & Desert Storm).
How much of the above relates to your grandfather depends of course on his actual dates of service with the battalion (he was inducted 17 March 1942 but it's anyone's guess as to when he joined the battalion - and when he was relieved).
Technician Fifth Grade was an army specialist rating equivalent (for want of a better term) to corporal, 5th Pay Grade.
The division veterans association might be able to put you in touch with one or more who served with him:
37th Infantry Division Association 65 South Front Street, Room 707 Columbus, Ohio43215-4158 (614)228-3788