This is the piece the steering wheel fits on to. Triumph managed to use 7 different part numbers between the beginning of TR4 production and the end of TR6 production.

None of these parts are available new, but we do have second hand parts kept under the global part number 156060SH. See below. There are 3 different overall lengths, 530mm, 548mm and 552mm, some are steering lock type and some are not. As follows 131503 Non Locking type TR4, 4A 141629 Locking type TR4A, 5, 250 141627 Non Locking type TR5, 250 149864 Non Locking type TR5, 6 (530mm) 149869 Locking type TR5, 6 up to CC/CP50,000 154640 Locking type TR6 from CC/CP50,001 156060 Locking type TR6 from CP52786

This part appears on the following Triumph Catalogue Plates

Car Type	Plate	Plate Title	Plate No.	Triumph Part Description	No per Unit
TR6CP	AH	STEERING	AH3C	STEERING COLUMN ASSEMBLY - UPPER OUTER (LOCKING TYPE) Right Hand Steering Fitted from CP52786	1
TR6CC	AH	STEERING	AH3C	STEERING COLUMN ASSEMBLY - UPPER OUTER (LOCKING TYPE) Right Hand Steering Fitted from CP52786	1
TR6CR	21-30	STEERING WHEEL AND INNER COLUMN	21-30	STEERING COLUMN ASSY UPP OUT LOCK TYPE RHSTG	1
TR6CF	21-30	STEERING WHEEL AND INNER COLUMN	21-30	STEERING COLUMN ASSY UPP OUT LOCK TYPE RHSTG	1