I guess I'll be tiresome again, but Adams and Jefferson were not friends. Adams was a Federalist and Jefferson a Democratic-Republican. It was pretty contentious between the two factions. I can't remember if it was the second or third presidential campaign- but it was BRUTAcorrespondence. They still had a lot of differences, but I think at a distance, they did very well
. I think the fact that they were some of the few (only?) remaining founding fathers maybe drew them together. They both really wanted to be around by the 50th anniversary of the Declaration, and died on that day. John Adam's last words were: "Thomas Jefferson still lives." Jefferson had actually died 5 hours earlier on the same day. L between the two.
I believe later in life, they were more friendly, but I don't think they were ever really close.