Lü Dai was already nearing the age of 80, but he was still in good physical health, competent enough to perform his duties as a general, and still personally saw to all the day-to-day affairs in Wuchang (武昌; present-day Ezhou, Hubei). Around this time, a Wu general Zhang Cheng wrote a letter to Lü Dai as follows: "In the past, when Dan and Shi served as regents of Zhou, people wrote the Odes of the South to praise them. Today, you and Master Lu are just like the two of them. Both of you demonstrate loyalty, diligence, hard work, and humility, make great achievements and contributions, and promote a strong civil culture. Junzis sing praises of your virtues while the people admire you for your values. I heard that every day you have piles of documents to look through and an endless queue of people to meet, yet you neither put aside your work nor complain that you are tired. I even heard that you can get onto horseback without stepping on the stirrups. It looks like you have surpassed Lian Po. How wonderful it is for you to have all these achievements! The Yijing says: 'He wishes his virtue to be more and more complete, and in his intercourse with others to be more and more respectful.' How did you attain such perfection?" In 243, Lü Dai sent Zhu Ying () and Kang Tai () to survey the lands south of Jiao Province in present-day Mainland Southeast Asia and spread Chinese culture there. Kang Tai wrote the Wu Shi Waiguo Zhuan (), which recorded what he saw during his travels in Mainland Southeast Asia. Following Lu Xun's death in 245, Zhuge Ke replaced him as the military commander guarding Wuchang and overseeing affairs in Jing Province. Sun Quan then divided Wuchang into two sections and put Lü Dai in charge of the right section, which oversaw the area from Puqi (蒲圻; present-day Chibi, Hubei) to Wuchang. In September or October 246, he promoted Lü Dai to Senior General-in-Chief (), and commissioned Lü Dai's son Lü Kai () as a Colonel to oversee the military garrison at Puqi. Later career and death After Sun Quan died in May 252, his youngest son Sun Liang became the next emperor of Wu. Later in May or June that year, Sun Liang appointed Lü Dai as Grand Marshal (). Lü Dai died on