Loose spelt on a whirlpool belt drive washer
Full size whirlpool washers never had any belt tensioning system, it was one of the major faults of these machines.
The belt would eventually get loose from normal wear and tear, and they typically failed when it would go into spin and the belt was so loose that when the spin clutch engaged, the belt would just stop moving in the motor kept running and the motor pulley would burn through the belt and the belt, of course failed often with the smell of burning rubber.
Whirlpool washers never had any trouble with the clutch grabbing after 1968 when they went to the three pad clutch, before that they had considerable troubles with the clutch grabbing, which is why the change was made.
Other than that, you guys are overthinking this whole belt issue. It was a simply a loose belt, which was normal of course it wouldn’t hurt to put a new belt on it, but it’s not going to be necessary for many years.
Whirlpool made a big improvement in these belts in the 70s. They put polyester cord in them, which actually tended to shrink as it got hot sometimes lessening the need for belt tightening, and also reducing the failure rate of the belt.
The drive felt was often one of the most replaced parts on belt drive machines, but it was also not unusual to see a machine that was 20+ years old with the original belt on it, much like Maytag dependable care machines some of them burn belts out in the first year others went for 30 years or more with the same belt, depending on how heavily the machine was used of course.
John L