I was issued a visa based on retirement in Australia in January 2014. I left Thailand and re-entered which extended the visa until January 2017.

i will be returning to Australia in November for three months so back here in early February 2017. Is it possible to extend my visa based on retirement before I leave ? I know the alternative is to go through the entire process again in Australia which was not the easiest thing compared to extension here. Thanks in advance.

The earliest you can apply for an extension of stay (it is not a visa) is 45 days at some office at others it is 30 days.

If you cannot do your extension before leaving you will have to start all over again by getting a new visa. If you don't want to go the OA visa route again you could get a single entry tourist visa and change it to a non immigrant visa at some immigration offices when you return and then apply for an extension.