Some original equipment alternators made in recent years feature a “floating stator” that is more sensitive to proper handling than previous designs. Previously, the stator — the set of windings that surround the rotor — in most alternator designs, is press-fitted or in a tight tolerance. In recent years, however, some manufacturers have chosen to center the stator in the alternator housing and simply clamp it in place, resulting in what is known as a floating stator.
The design works great, but it’s more sensitive to proper handling than previous designs with press fitted stators. If an alternator with a floating stator is subjected to undue shock during the shipping or installation process, the stator actually can “float” out of concentricity. This floating stator can result in a noisy alternator, an alternator that rubs internally, or even one that is locked up or won’t turn at all.
How do you know? Look for a warning label on the alternator, alerting you to handle the alternator with care. Each Bosch remanufactured alternator, for instance, that features a floating stator comes with a quite obvious warning label. The warning label states, “Prying on the external housing for alignment or tensioning of drive belt and/or rough handling of the part will result in internal damage.” Keep your customers happy and avoid comebacks by using care to handle alternators with floating stators.
Source: Robert Bosch LLC