The MGB steering column changed significantly across production, and selecting the correct replacement parts depends entirely on knowing which column type your car is fitted with. There are two fundamentally different designs: the non-collapsible column fitted to early cars, and the collapsible energy-absorbing column that was progressively introduced across markets from 1967.
Non-Collapsible Column
Early GHN3/4 and GHD3/4 cars used a non-collapsible column, available in two inner and outer tube combinations depending on whether a steering lock was fitted. GHN5 and GHD5 cars up to chassis 258000 continued with a non-collapsible column in a revised configuration. The non-collapsible column is a solid assembly that can be serviced with standard upper and lower bushes, the lower bush is available in felt in both steering-lock and non-steering-lock types, and the upper nylon bush is a direct-fit improvement over the original felt type.
Collapsible Column
The collapsible energy-absorbing column was introduced on North American cars from the Mark II in late 1967, and was fitted to non-North American cars from chassis 258001 in August 1971. From the start of rubber bumper production in 1974, all markets received the same collapsible column. Two rubber bumper column variants exist, one for cars up to September 1976 and one for cars from September 1976 onwards. These later energy-absorbing columns use a pierced cage outer construction which, once crushed in an impact, cannot be repaired, the bearings are not available as a new component, making secondhand sourcing the only route in the event of damage.
The upper and lower bushes for collapsible columns differ from those used on non-collapsible types and must be matched accordingly.
Column Spline Types
Four distinct column spline types exist across the production run, 1962 to 1967, 1968 to 1969, 1970 to 1976, and 1977 to 1980. This means steering wheels are not interchangeable between these periods, and the correct boss kit must be matched to the column spline when fitting an aftermarket wheel.
Universal Joints
The column connects to the steering rack via a universal joint assembly. Chrome bumper cars up to chassis 258000 use the earlier type, while later chrome bumper and all rubber bumper cars use a revised universal joint and coupling assembly. The UJ differs in size between chrome bumper cars (4-inch) and rubber bumper cars (3¼-inch), and the two are not interchangeable. Correct alignment between the base of the steering column and the top of the rack input shaft is essential, misalignment here produces uneven steering feel through the wheel and accelerates wear in both the rack and the column joint.
The pinch bolt securing the UJ to the column and rack pinion is a critical safety fixing that should always be replaced rather than reused. The column-to-bulkhead seal, lower mounting bracket, column clamps, and distance tubes all vary between column types and should be checked when ordering. Important safety note: undue force applied when removing or refitting the steering wheel, column bushes, or any column components on a collapsible column can permanently collapse the column. Always use a correct steering wheel puller for removal, improvised methods risk damaging the column and disturbing the inner shaft. This work should be carried out with care, or by a qualified workshop.