My understanding is that the transfer switch default is the genertor and should not clunk when going to or on the generator. Since it is a mechanical switch, will only clunk when shore power is applied and then again when disconnected and going back to the default position of the generator. Next time when disconnecting from shore power going to listen for the clunk. Only thinking.
2011: 54 days, 2012: 218 days, 2013: 175 days, 2014: 196 days
2015: 188 days, 2016: 72 days,
2009 Berkshire, 390QS, and toad