The MGA front stub axles and hubs are among the most variant-specific components in the front suspension, because they are paired to the car's front brake type and wheel type. The 1500 uses Lockheed drum-brake hubs. The 1600 and 1600 Mk II use Lockheed disc-brake hubs. The Twin Cam and De Luxe use Dunlop disc-brake hubs with centre-lock disc wheels.
Within each of these brake specifications, disc-wheeled and wire-wheeled cars use different hub arrangements, because the wire-wheel knock-on fitting requires a different hub end to the plain disc-wheel stud-and-nut fitting. Accurate parts selection therefore requires confirmation of both the brake specification and the wheel type for the car in question.
1500, Lockheed drum-brake hubs
Pushrod 1500 MGAs use drum-brake hubs appropriate to the 10-inch Lockheed drum-brake installation at the front. These hubs are specific to the 1500, they are not interchangeable with any disc-brake car's hubs. Within the 1500 range, disc-wheeled and wire-wheeled cars use different hub specifications: disc-wheeled cars use a bolt-on plain disc fitting; wire-wheeled cars use a splined hub to accept the Dunlop 48-spoke wire wheels with their centre-lock fixing.
Replacement hubs, stub axles and hub bearings are available for both disc- and wire-wheeled 1500 configurations.
1600 and 1600 Mk II, Lockheed disc-brake hubs
The 1600 and 1600 Mk II use Lockheed disc-brake hubs, different from both the 1500 drum-brake hubs and the Twin Cam Dunlop disc-brake hubs. As with the 1500, disc-wheeled and wire-wheeled variants of the 1600 and 1600 Mk II use different hub specifications. The front disc-brake studs for attaching the brake discs to the front hubs were revised at car/chassis 69505 (disc-wheeled cars) and 70276 (wire-wheeled cars), when studs were replaced by bolts, a change that affects disc-mounting hardware orders for cars either side of that breakpoint.
Twin Cam and De Luxe, Dunlop disc-brake hubs
The Twin Cam and De Luxe use Dunlop-manufactured 11-inch disc brakes at the front and four-wheel disc brakes in total. Their hubs are specific to the Dunlop installation and are not interchangeable with any pushrod MGA hub. The Twin Cam uses centre-lock Dunlop disc wheels made from steel with 15 ventilation holes, driven through peg drive to the hubs rather than the splined drive used for pushrod wire wheels. The knock-ons for the Twin Cam centre-lock disc wheels have a coarser thread than those found on pushrod wire-wheeled cars, and neither the hubs nor the knock-ons are interchangeable with pushrod items.
Twin Cam knock-ons were modified at Twin Cam car/chassis 1826, with the material changing from steel to bronze. Twin Cams supplied to Germany have octagonal spinners from car/chassis 708 in place of the standard knock-ons. The De Luxe variants carry over the Twin Cam wheel and hub architecture along with the later-type knock-on and octagonal spinner options.
Pushrod wire wheel knock-ons
For pushrod MGAs fitted with wire wheels (optional on all pushrod variants), the Dunlop 48-spoke wire wheels attach to splined hubs via centre-lock knock-ons. The standard pushrod knock-on originally carried the MG badge in the centre, with "right (off) side" or "left (near) side" markings and an "undo" arrow in the appropriate direction. The knock-ons were changed twice during 1500 production: at car/chassis 40857 to a more curved section across the centre of the knock-on, and again at car/chassis 48730, the last type not carrying the MG badge. Octagonal spinners were introduced on pushrod cars for Germany around car/chassis 57500 in October 1958, and were subsequently also fitted for the Swiss market; these octagonal spinners never carried the MG badge.
Replacement knock-ons, their drive splines on the hub side, and the associated hub components are available in both original pattern and later-pattern specifications.
Rear hub lock nuts
A related detail covered under the rear axle (Node 2649) but relevant when ordering: on the 1500, handed rear hub lock nuts with a left-hand thread on the left-hand side of the car were introduced from chassis 10917 (disc-wheeled) and 11450 (wire-wheeled). Earlier 1500 cars use right-hand-thread lock nuts on both sides. This affects rear hub nut orders alongside any front hub work.
Ordering considerations
Front hub and stub axle orders require three criteria to be confirmed: the variant (pushrod 1500, pushrod 1600 / 1600 Mk II, Twin Cam or De Luxe), the front brake specification (Lockheed drum, Lockheed disc or Dunlop disc, determined by variant in factory specification, but cars that have been converted between brake types over their service history may now differ from original), and the wheel type (disc or wire).