I have TRC's 30 Amp
Portable Surge Guard. There have been times I have plugged it in and after 128 seconds it passes the self-test. THEN a bit later I walk by the pedestal and the relay inside it is chattering continuously. I shut the breaker off, plug in a 50-to-30 amp dogbone in the 50 amp side, and plug in the Surge Guard - and it is happy. The 30 amp side of the pedestal was faulty.
Your
50A Hardwire - Model 41260 Automatic Transfer Switch has basic surge protection properties, but has no status indicators to show what is tripping it.
Where am I going with this? Your transfer switch's hammering sounds like my surge protector's freak out over bad power. Have you tested the pedestal? It could be a bad breaker, a loose terminal causing a short, or ground issue. There may be nothing wrong with the transfer switch.