Due to the LED gimmick being neutered, Grimlock's beast mode bottom jaw can be slightly loose, leaving his mouth always open.
So I opened up Battle Grimlock and I'm not seeing this. The jaw isn't loose at all and none of the parts that were associated with FOC Grimlock's LED are even present on the figure.
The beast mode t-rex arms, on the other hand, love to pop off.
So is the TFwiki write up an isolated incident that somehow got passed off as fact, or does anybody else have a Battle Grimlock with a slightly loose jaw?