'05 Silverado Firewall Question

[TXFXR]

Long story short I had a lifter go out so I built a heads/cam motor. I was wanting to add another ground and pulled this bolt. When I did I heard something "fall" sounding like it was in the dash in the cab. Does anyone know what this goes to and if so how I can get to it? Now I have a thud noise after I hit bumps and its very annoying. 

[TXFXR]

Nobody? 

[carnau]

On 1/18/2021 at 10:53 AM, TXFXR said:

Long story short I had a lifter go out so I built a heads/cam motor. I was wanting to add another ground and pulled this bolt. When I did I heard something "fall" sounding like it was in the dash in the cab. Does anyone know what this goes to and if so how I can get to it? Now I have a thud noise after I hit bumps and its very annoying. 

It's the bolt that holds the HVAC box to the firewall. If something fell that means the case retainer is cracked and fell down. Here is a picture.

[TXFXR]

On 1/19/2021 at 5:16 PM, carnau said:

It's the bolt that holds the HVAC box to the firewall. If something fell that means the case retainer is cracked and fell down. Here is a picture.

I had pulled the bolt out to add a ground and heard something fall when I pulled it, not that something broke. I looked everywhere for a diagram like that and appreciate you sharing that! Is there a way to run the bolt back into the HVAC box without pulling the dash out? 

[Gagliano7]

If you get lucky and it is still lined up. If it dropped i would assume you need to raise it up from inside. Might get lucky and look up from gas pedal area and use some kind of rod to push up if it indeed dropped.