Newbie black tank valve access question

[chrishunnicutt]

2nd shakedown trip in our 2013 3750FL was a great trip. No issues to speak of until at the dumping station. Hooked up my rinse down hose and started the rinse down before pulling the drain. Added enough water to get the tank to read at 3/4 full and add volume for flushing. I have a close off valve at my bayonet fitting and that was open. I pulled the black tank release and it started to empty. I let it run until it started to run clear then I shut the black tank valve to allow it to fill up again. After a few minutes I pulled the black tank release again and allowed it to run clear. I didn't have anyone waiting so I decided to run the cycle one more time. I ran it a third time and noticed some tension in the release valve tension. It opened and cleared. I turned off the rinse down and emptied my gray tanks. When I went to go close the black tank valve it wouldn't budge. It actually has a little play in like the far end has come loose. My concern is that even though I have a safety valve at the bayonet I have no way to close off the black tank.
How do I get to the far end of the pull rod? I can hear it moving when I try to pull it out or push it in. Whats the best way to lower the belly cover? I have an extended bumper to hitch warranty but I'm hoping its a quick fix I can do myself without having to carry it in to the closest Camping World. Any help or input is greatly appreciated.