Alegro is a quality RV, and like all of the other manufacturers, they use A Ford of Chevy chassis on that size RV. During the era, both had some inherent problems, like poor suspension, cracked headers on the engine and so on.
How well the chassis is holding up is a direct reflection of how well it was maintained or how ell it was treated in general with little regard to the mileage.
With proper care and not being abused, these chassis and engines can make 100,000 miles. I would ask the owner to see his maintenance records.
Low generator hours and low mileage can also be a problem. depends on maintenance.
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