Wire wheel spinners are both a functional fastener and one of the most visually defining details of a wire-wheeled car, and getting the specification correct is essential for both safety and operation. On the MGB and MGC wire wheels were a factory option, while the MGB GT V8 left the factory on alloys, so spinners apply to V8s converted to wire wheels.
Handing & Thread Pitch
Spinners are handed, the right-hand side of the car using left-hand thread spinners and the left-hand side using right-hand thread, so the rotation of the wheel during forward driving tends to tighten rather than loosen them. If hubs have been swapped between sides by a previous owner the spinners will work loose in normal use, so hub orientation must be confirmed before driving. The hub spline thread pitch changed during production, cars to chassis GHN3-30850 in approximately February 1964 using 12 threads per inch, with all subsequent production using 8 threads per inch, and the correct pitch must be matched to the hub as the two are not interchangeable. Both knock-ons and octagonal nuts had an altered section for increased strength from car number 28951 in January 1964 but remained interchangeable with the earlier versions.
Spinner History & Identification
Knock-ons and octagonal nuts of all types were made of chrome-plated aluminium bronze and carried the words 'Right Side' or 'Left Side' and 'Undo' with directional arrows, but never the MG logo. Wire wheel spinners were originally of the two-eared type on UK cars until sometime in 1968, when they were replaced by octagonal nuts on safety grounds. Octagonal nuts had already replaced them in markets where wing nuts were illegal, and from the start of MkII production in late 1967 all export cars had octagonal nuts, with home market cars following in August 1968. Eared spinners are tightened and loosened using a copper-faced mallet, while octagonal nuts can be tightened with a standard octagonal wheel brace, which many owners find more convenient at the roadside.
The two types are interchangeable on the same hubs provided the correct thread direction is maintained for each side.
Range & Care
All three types, two-ear, three-ear, and octagonal, are available in both 8 TPI and 12 TPI thread pitches, in left and right hand versions, with and without MG logo. Stainless steel spinners and octagonal nuts are available for owners seeking a longer-lasting finish than chrome plating, which eventually develops corrosion beneath the plating layer. The two-ear spinner spanner, octagonal spinner spanner, and plywood spinner saver are available for correct handling. Spinners should be checked for security before every journey, and the cone face that contacts the hub should be lightly greased to allow proper seating without seizing, as worn spinner or hub cones cause the wheel to wobble and must be addressed immediately given the safety implications.