Bertie,
Another check that you could add to the PA-28 ( & prob other types ) is the propeller drive belt tension
Unless I'm very much mistaken, the prop on a PA28 (and most aircraft, in fact) is bolted straight onto the front of the engine - it's not driven by a belt. I'd imagine the belt you're thinking of is the alternator drive belt? (The only piston engine I'm aware of - although I'm sure there are others - where the prop doesn't bolt straight onto the front is the Rotax, and that uses a gearbox rather than a belt to drive it.)
FFF
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