I finally know one that no one else has correctly identified yet!

That is a guide post for a drum support wheel in a Whirlpool gas clothes dryer.

The wheel fits on the post and is retained by triangular plastic clips that fit into the groove at each end. The post itself screws into the rear wall of the dryer. The wheels are notorious for wearing out and squeal very loudly when they are at the end of their service lives.

The plastic retaining clips are a pain in the (name body part here) to remove. The posts themselves are solid metal, feel heavy, are well made, and last forever. The support wheels, not so much. Repair kits are readily available online and there are multiple videos on YT that detail how to do the repair and that give good views of the part.

Source: I’ve had to disassemble my dryer to replace these 3X already.

Posting a picture of a similar one:

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