loud clicking / clunking noise when putting in park

[Bad Max]

When putting the transmission in park with foot on the brake and then release brake, there is a loud click/ clunk noise on the driver's side floorboard? It can be felt and heard. What is the problem? It was not like that before, but was I running the truck hard with Bully Dog in 4WD for the first time but did not like it, felt a vibration shortly after turning the 4WD off after takeoff with settings on Performance.
I felt a noise there on the floorboard a while back but did not think much of it.

Bad Max

[DmaxMaverick]

Sounds normal. The Allison's parking pawl is considerably more robust than in other autos, and will clunk on ocasion during engagement. Back during the 2001 truck introduction, many new owners received a video from Allison explaining the different characteristics of the new tranny. This clunk was explained as normal. Mine does it and always has, just not all the time. I think you can still access the old documents from Allison at their website, which also explains this.

[Bad Max]

Tech says it is the solenoid that makes the noise when you park, normal for Chevys. Thanks
Bad Max