Anybody have any idea how I would go about tightening a metal rod joint?

[Trelane]

Not sure if this is the right place to post this, but it's about a modern toy, so...

I bought my first Transformer in over 5 years today, transformed him, and realized his foot joint is very loose. I stuck a small piece of paper between the foot and the leg, and it's almost unnoticeable, but it still doesn't feel quite right. I don't want to return it, because he was half off and the only one left. Plus he looks pretty bad*ss.
The joint is one of those small metal rods, and I have no clue how I'd go about tightening it. Any suggestions? I can provide pics as well in case no one knows what I'm talking about.

[Gorn Captain]

I've tightened joints with superglue.
Put just a little bit on, and keep the joint moving as the glue sets. The small layer of residue is usually enough to provide some friction.

If you end up with an immovable joint, I live in Europe, so you'll never hunt me down....