"North Carolina" returned to Pearl Harbor in March for a refit that lasted for more than a month and included the installation of radars and improved fire control equipment. On returning to the South Pacific, she joined the battleship group of TF 36, now commanded by Rear Admiral Glenn B. Davis and consisting of "Indiana" and . The battleship and carrier groups covered amphibious assault forces during Operation Cartwheel, the campaign to isolate the Japanese stronghold at Rabaul, in late June and early July. They did not see action during the campaign, as fighting was limited to both sides' light forces. In September, she made another trip to Pearl Harbor to make preparations for the attack on the Gilbert Islands.