Hey y’all. New to the forum. Just picked up a super clean 2005 Limited Roadster.

Needed a new alternator so I swapped that out yesterday. When I took the belt off. The top idler pulley separated into two spools off the rotating hub. Is this normal design? I’ve never seen a non fixed two piece pulley wheel like this before.

I’m referring to the actual pulley wheel with the grooves in it. When the belt came off, the front and back portions of this pulley came apart right in the middle on the rotating hub bolted to front of engine. It doesn’t look broken. The central hub is sprocketed and the pulley pieces are grooved to fit onto these sprockets. When the belt is back on and under tension, it holds the two pieces of the pulley together and in place and everything spins just fine.

Is this a normal design???? Or was the pulley wheel originally adhered together on the central hub and for whatever reason has come apart at any potential seam in the middle?

Thanks