The instruments are among the most chassis-number-dependent components in the catalogue. The TD alone has three speedometer specifications, two rev counter specifications, two ammeter types, and a transition from separate oil pressure gauge to combined oil-and-water-temperature gauge. The TF introduced an entirely different set with three octagonal centre-panel gauges and larger main instruments facing the driver. All were Jaeger (some Smiths on the TF), with silver grey-green dials, brown figures, and T-series green rim lighting.
TD Speedometer Specifications
Three TD speedometers exist, all reading to 105 mph with a five-figure odometer and trip with re-set. Early TDs to chassis 10778 RHD/10750 LHD used a flat-faced chronometric (TC-style); from 10779/10751 to 17547 a dish-faced magnetic replaced it; from 17548 the dish-faced gained a high beam warning lamp. Each is supplied on a customer's own unit reconditioned basis. New reproductions are available for the flat-faced type.
KPH versions are catalogued for export. Face metal and decal restoration sets are available.
TD Rev Counter and Clock
The TD rev counter reads to 6,500 rpm with an electric clock in the lower portion. It exists in two specifications matching the speedometer changeover: flat-faced chronometric to chassis TD/10778 (RHD) / TD/10750 (LHD) (also a new reproduction) and dish-faced magnetic from TD/10779 (RHD) / TD/10751 (LHD). Both are catalogued on a customer's own unit reconditioned basis.
TD Ammeter and Oil Pressure Gauge
The ammeter changed at the same chassis 10751/10779 instrument changeover, with a different scale and design, both versions available as reproductions and on a customer's own unit reconditioned basis. The oil pressure gauge changed at chassis TD/13914 (February 1952): the original Smiths gauge (clockwise to 160 psi) was replaced by a combined oil pressure and water temperature dual gauge. Optional water and oil temperature gauges were available throughout TD production, with specification matching the chassis-number bracket.
TD Instrument Hardware
Two-inch gauge glasses, chrome rims, O-rings (glass-to-gauge and gauge-to-dashboard), and knurled mounting nuts are universal across all auxiliary instruments. Speedometer and rev counter glasses and clamps differ between flat- and dish-faced specifications. The high beam warning lamp on later TD speedometers uses its own bulb holder.
TF Instruments
The TF instruments are completely different. The speedometer (with integral clock) and rev counter are larger main instruments directly in front of the driver, with ammeter, oil pressure, and water temperature gauges in a centre panel of three octagonal glasses with chrome rims, a TF detail drawn from the MG logo. All TF instruments are supplied on a customer's own unit reconditioned basis. A police-specification speedometer is catalogued for UK police cars.
A remote trip-reset operates the speedometer trip.
Speedometer and Rev Counter Cables
The speedometer cable runs from gearbox to dashboard. Lengths: TD RHD 5'8", TD LHD 6'6", TF RHD 6'3", TF LHD 5'8". The rev counter cable runs from dynamo to dashboard via a reduction gearbox, a TD/TF-specific arrangement requiring a dynamo with tachometer drive. Cable lengths are 4'0" RHD, 3'6" LHD.
A short drive cable connects dynamo gearbox to rev counter cable (4'0" RHD, 3'4" LHD). Reduction gearbox, coupling kit, and grease nipple are individually available.
Oil Pressure Pipework
The oil pressure gauge on both models is a mechanical Bourdon-tube gauge fed by a small-bore oil pipe from the engine. A flexible hose runs from the block to a bulkhead adaptor, then a rigid pipe to the gauge. A leather sealing washer is fitted at the engine connection. Modern stainless-braided hose is available as an alternative to the original rubber.
Temperature gauge capillary pipe adaptors come in male/female and male/male thread configurations.
Dashboard Illumination
Dashboard illumination uses individual bulb holders behind each instrument with TD-specific brackets fitted to the early TD instrument panel. The bulb specification is the same low-wattage type used for the warning lamps and high beam indicator, simplifying spares carriage.
Ordering Considerations
Chassis number determines speedometer (three TD types plus TF), rev counter (two TD types plus TF), ammeter, and oil gauge (separate or combined). Drive side and model determine cable lengths. The TF police-specification speedometer should be confirmed by original specification. Most instruments are supplied on a customer's own unit reconditioned basis, the existing unit is rebuilt, preserving the original face and character.