I was reading up on the M48 and the wikipedia page mentioned here that, while the rest of the US Army's stock of M48s were relegated to Reserve and National Guard units, the 2nd Infantry Division traded their own M60 tanks for M48A5s in 1978. Why did this occur, when the 2nd Infantry was in position on the Korean DMZ, a notorious hotspot of conflict, especially considering the exchange took place only two years after the Axe Murder Incident.
It seems that the Wiki page is basically quoting from Hunnicutt, although it doesn't source it in the footnote.
The full Hunnicutt entry is as follows:
"The majority of the M48A5 tanks were destined for the US Army Reserve and National Guard units. However, 140 M48A5s were deployed to Korea to replace the M60A1 tanks of the US 2nd Infantry Division. The first two of these tanks arrived at Pusan, Korea, on 8 June 1978 and were issued to the units eight days later. The final tanks were handed over on 21 July. The M60A1s were then returned to the United States for a badly needed overhaul."
So, it seems to merely be a matter of availability. 1978 is about the time that M60A3s started production (or conversion from M60A1s), and hotspot or not, Korea was still second fiddle to Germany. So, as the new vehicles were coming off the production lines, they went to Germany. It seems that Eighth Army were given a choice between keeping clapped-out, probably unreliable M60A1s, or taking, for at least a while, M48A5s which were only 90-95% as good, but factory fresh.