check the axle tubes they are just a u shaped channel iron that manure sits in & rots out the channel . when a axel breaks on the left side you can kiss your gearbox goodby & they are small , all manure spreaders are small no matter how big they are .
Those apron chains are pretty well indestructible as long as they don't go slack. If they start to get too much slack, they will fall apart like a loose puzzle and then you will be hunting for lost links all over the field . . .