Sergeant Major Gruber graduated from recruit training at the Marine Corps Recruit Depot (MCRD) Parris Island, South Carolina in June of 1995. He then attended School of Infantry (SOI) at Camp Geiger, North Carolina.
Upon completion of School of Infantry (SOI), Private First Class Gruber reported for duty to Weapons Platoon, Fox Company, 2d Battalion, 2d Marines (F 2/2) as an infantry machine gunner. While assigned to Fox Company, Lance Corporal Gruber deployed on the 22d Marine Expeditionary Unit aboard the USS Guam in January 1996 and participated in Operation Assured Response, at the United States Embassy in Monrovia, Liberia. In June 1998, Corporal Gruber deployed again with F 2/2 on the 22d Marine Expeditionary Unit as a Team Leader aboard the USS Saipan. While deployed, he participated in a security mission at the United States Embassy in Tirana, Albania.
In March 1999, Sergeant Gruber reported for duty to Marine Security Guard School (MSG) at Quantico, Virginia. From May 1999 through May 2003 he served as a watch stander and finally as Assistant Detachment Commander at the American Embassies at Nicosia, Cyprus; Kathmandu, Nepal; and Rome, Italy. In May 2003, Staff Sergeant Gruber reported for duty to the Pentagon as a Security Team Leader at the National Military Command Center where he provided internal security for the Joint Chiefs of Staff.
In June 2004, Staff Sergeant Gruber reported for duty to Echo Company, 2d Battalion, 6th Marines (E 2/6) where he served as a Platoon Sergeant and deployed to Fallujah, Iraq in September 2005 in support of Operation Iraqi Freedom. In March of 2007, Gunnery Sergeant Gruber deployed again to Fallujah, Iraq with E 2/6, this time as a Platoon Commander in support of Operation Iraqi Freedom.
Upon completion of his combat tours, Gunnery Sergeant Gruber reported for duty at Headquarters Company, Headquarters and Service Battalion “The Beast” in Quantico, Virginia and served as the Company Gunnery Sergeant from December 2007 through February 2011.
In February 2011, First Sergeant Gruber reported for duty as the Company First Sergeant for Company I, 3d Battalion, 5th Marines (I 3/5). First Sergeant Gruber deployed on the 15th MEU from September 2012 to May 2013 and then transferred to Company K, 3d Battalion, 5th Marines (K 3/5) as the Company First Sergeant.
In December 2013, First Sergeant Gruber reported to Communications Company, Headquarters Battalion, 1st Marine division for duty as the Company First Sergeant.
In January 2015, First Sergeant Gruber reported for duty at Combat Assault Battalion (CAB), 3rd Marine Division, Okinawa, Japan.
In February 2016, Sergeant Major Gruber reported for duty at Marine Wing Headquarters Squadron 1 (MWHS-1), 1st Marine Aircraft Wing, Okinawa, Japan to serve as the Squadron Sergeant Major.
In February 2018, Sergeant Major Gruber reported for duty at Marine Light Attack Helicopter Squadron 469 (HMLA 469), 3rd Marine Aircraft Wing where he deployed on the Unit Deployment Program 18.2 attached to Marine Aircraft Group 36 in Okinawa, Japan.
In October 2019, Sergeant Major Gruber reported to the School of Infantry West, where he currently serves as the Regimental Sergeant Major.
Sergeant Major Gruber’s personal awards include the Purple Heart Medal, Meritorious Service Medal with one gold star, Navy and Marine Corps Commendation Medal with 2 gold stars in lieu of third award, Joint Service Achievement Medal, Navy and Marine Corps Achievement Medal with 2 gold stars in lieu of third award, and Combat Action Ribbon with one gold star.