The defending German champions recently announced that they will be parting ways with the former Barcelona and AZ boss in the summer, after a disappointing season so far. The Munich-based club are struggling for a top-three finish in the Bundesliga and have been knocked out of the DFB-Pokal recently.
Kahn, who played for Bayern between 1994 and 2008, believes that they need a long-term replacement, and told Munich's Tz newspaper: "They need to take their time and find a man who they can look for continuity with. Bayern need continuity again, none of this permanent changing of coaches.
"If you look at what has happened following the golden era of [Ottmar] Hitzfeld - [Felix] Magath, [Juergen] Klinsmann, [Jupp] Heynckes, Van Gaal - that is too many coaches. Nobody knows better than the management of FC Bayern that continuity is extremely important in the coaching position."
However, the 41-year-old believes that news of the eventual departure of Van Gaal will not affect the players between now and the end of the season, and insisted that Champions League qualification is within reach.
"It is always made out that the team is 100 per cent dependent on the coach, but I cannot imagine a single player at FC Bayern wanting to go through the Europa League next season," he said.
"The attraction of the Champions League, particularly with the 2012 final being in Munich, is immense."