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Lucas Round Axillary lights

This page covers Lucas round axillary lights optionally used on many 1950s and 1960s British cars. It does not include versions made specifically for Rolls Royce.

Lucas 576 lamps


Light types:

Early Lucas round auxiliary lights were 7 inches in diameter.  Around 1953 production of the 5-3/4 inch diameter auxiliary lamps began. Production ended sometime in the 1980s and very good quality reproduction lamps replaced them During the 1990s.  Concerned about trademark lawsuits, Moss Motors reproductions were labeled "Moss" where the Lucas name goes at the top front of the lamp. They later started offering reproduction lamps labeled Lucas. The reproductions are quite good and can only be identified by the lack of secondary label markings.

SFT = clear fog lamp, bottom mount
FT = yellow fog lamp, bottom mount (French specification)
SLR = long range driving lamp (AKA Flamethrower), bottom mount
WFT = fog lamps, rear mount
WLR = Long range driving lamp, rear mount
576 = 5-3/4" diameter
700 = 7" diameter

Complete lamp part numbers:

SFT576 = 5-3/4" diameter fog lamp = Lucas 551128
SLR576 = 5-3/4" long range driving lamp = Lucas 55132E (55257A for France)
FT576 = 5-3/4" yellow fog lamp = 552333A/B for sale in France and optional in other countries

Lucas 576 driving lamp side view
SLR576 "Flamethrower"




Lamp Housing:

There is one style of housing used for the 5-3/4" type 576 housing, both genuine and aftermarket. The only real changes were the existence of a top rib on the top lens clamp and stamped labeling.

Top clamp for 576 hiousing
Genuine Lucas lamp housings are stamped near the bottom. Aftermarket housings are not stamped.

Lamps made specifically for Jaguars have a longer bottom mounting stud and different nut. The removable bottom clamp locks the lens into place and is attached by a single chromed screw (Lucas 144921). There is a black 1/16" thick rubber pad 7/16" X 5/16" glued to the top and bottom clamps that protect the lens from cracking when mounted.


Top clamp for Lucas 576 lamp
Both genuine and aftermarket top lens clamps are stamped "LUCAS" except for reproductions sold by Moss during the 1990s. Moss was concerned about being sued for trademark infringement. They later sold aftermarket lamps marked LUCAS.  Note that the labels are red. The white is old polish.


It is not uncommon for the threaded bottom mounting stud and its nut to become rusted requiring them to be cleaned up with a tap and die. The thread is British Standard Bicycle (BSC) 5/8"- 26 tpi, 60 degree pitch.

top clamp for 576 lens

Top lens clamps:

BOTTOM: The early genuine LUCAS top lens clamp had a smooth top.

TOP: The later genuine and aftermarket lens top clamps have a raised ridge along the top.

Lucas 576 mounting threads
There are two lengths of mounting studs. Genuine Lucas for non-Jaguars is 1-3/8" long below the housing.
Genuine Lucas for Jaguar and aftermarket 576 lamps both have a 1-15/16" or 2" long mounting stud below the housing,



There were 2 types of lens, a fog light lens and a clear long range lens. The fog light lens came in either clear or yellow. The yellow was specifically for the French market and was optional for other countries. There is a silvered front reflector mounted inside the lens and screwed to a external bullet shaped metal piece on the outside centre of the lens. The purpose of this front reflector is to reflect the light from the special bulb back into the rear lens reflector to provide more focused light out the front.  Again, the reproduction lenses are very good quality and the only way to identify the genuine Lucas lens is by looking at the markings on the front of the lens.

Lucas 576 fog lamp
The genuine Lucas clear fog lens is marked "Made in England" at the bottom front and "M5" just above


Lucas yellow 576 fog lamp
The genuine yellow fog lens is marked "LUCAS" just above the metal bullet at the centre of the lens, "FT576" vertically near the middle left (looking at the lens), and "Foreign glass AMT" at the bottom font


576 long range driveing lght, flamthrower
The genuine clear long range driving light lens is marked "England" at the bottom, and "M5" a little above it. Aftermarket lens is Just labeled "TOP" near the top of the lens.


Lens part numbers:
Clear fog = Lucas 554813
Yellow fog = Lucas 554820
Driving lamp = Lucas 554816

Labels on 576 driving lamp
Markings at bottom of lens: "Made in England" and "M5"



The socket locks the bulb into place at the back of the lens, provides electric connections to the bulb, and its rubber stand offs push against the back of the housing to keep the lens from rattling against the housing and keep the electrical connections firmly against the bulb. There are two versions. The early version is black Bakelite (Lucas 554667) and a later brown phenolic version (Lucas 54520352).

early 576 lamp socket
Early black Bakelite socket (Lucas 554667)


late 576 lamp socket
Later phenolic socket (Lucas 54520352)



The original bulb is a single transverse filament type (filament pointed to base) . There is a notch in the BPF base flange to correctly line the filament up with the front reflector to properly direct light back to the rear reflector.  Lucas LLB185, 12V, 48 watts. This bulb was used in both the 576 and 700 series of lights.

Note that these have been replaced with an aftermarket bulb that has a filament perpendicular to the base that also uses the same LLB185 part number on a Lucas labeled box. The front internal reflector was not designed to properly reflect this new filament location which means the driving light beam will not be as focused. The new bulb is rated 12V, 45 watts. There are also amber bulbs that will allow a clear lens to produce an amber light, LLB 323Y, 12V, 48W.

I have found 2 versions of markings on the original style LLB185 bulb. One version just has 12V 48 W stamped into the side of the base above the flange. The other is marked in white at the top of the bulb glass. There is a circle with "B" above "TH" in the circle.  Outside the circle is "made in England" and "12V 48W". This appears to be the earlier version of the two.

Halogen bulbs are offered for this use as are brighter lower power LED bulbs. Some of the higher power halogen bulbs have been known to produce enough heat to crack the lens. The LEDs have cells pointed to the front and sides that while brighter and lower power, produces a wider less, focused light.

Lucas LLB185 bulb

12V 48W

Switch and Panel:

Most British cars did not come with auxiliary lighting as standard, so when added the switches were usually placed on an auxiliary panel screwed to the underside of the instrument panel. The most commonly used panel was the Lucas PS-7 which had two holes. When a single switch was used, the other hole had an indicator light. When two different auxiliary lamps were used, the panel held two switches. The knob for a fog lamp was either labeled "F" or "FOG". The knob for the long range driving lamp was labeled "LR". The common Lucas push - pull switch was used (Lucas 31434)

Lucas PS7 auxillary switch panel

Lucas PS7 switch panel with 2 Lucas 31434 switches


New lamps and replacement parts:

Moss motors offers new 576 series aftermarket lamps and replacement parts to allow you to repair your lamps. For some reason they tucked the page away in the section for MGA electrical parts so most people could not find it. They offer complete lamps with the longer Jaguar attachment studs.





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