Before ordering any parts, it is essential that you have full details of the chassis number, engine number, body number, rear axle and gearbox numbers.
The commission or chassis number on early TR6 models was mounted on plates affixed to the top of the inner left hand front wing. The plate included the commission number which could have a suffix “L” OR “U” (1971 on) for left hand drive models, and “O” for overdrive.
Later TR6 models had the commission plate attached to the left hand ‘B’ post, below the door shut plate.
Two plates attached to the bulkhead were body numbers. One was fitted by the manufacturers of the bodyshell, the other by Triumph. These numbers are not required when ordering replacement parts.
The engine number was stamped onto a lip at the rear of the left hand side of all engine blocks, just visible below the spark plug. The engine number is essential when ordering engine parts.
The gearbox number is stamped onto the casing just behind the clutch lever crosshaft box. On later USA models the number was stamped above the starter motor bulge on the right hand side of the gearbox casing. Use this number when ordering gearbox parts.
The rear axle number is located at the base of the axle housing, when viewed from beneath the car. Use this number when ordering axle parts.
Vehicle Commission Numbers & Component Serial Numbers. Wherever identification numbers are quoted in this catalogue (to help you to distinguish Factory changes/years), they relate to the Original Factory Specification or Component(s) when the vehicle was new and not subsequent or miscellaneous replacements.
Evolution of the TR Range
The TR6 was the last link of a long evolutionary trail
that dated back to the early 1950's, and perhaps even
earlier. The TR story started in 1952 when Harry
Webster's design team, along with body designer Walter
Belgrove, showed their concept of a new ‘Triumph Sports
Car' at Earls Court. Public reaction proved positive and
over the following winter Webster's team worked hard to
develop a production model.
Based on the Standard Vanguard wet liner engine, a
sturdy Flying Standard Nine chassis and front suspension
from the old Triumph Mayflower, Belgrove's team
introduced the TR2 to an excited public at Geneva. From
here on the evolutionary process began that led to the
TR5 and finally the TR6.
Following minor facelifts and engine alterations seen
in the TR3 and TR3A models, the TR grew into a more
sophisticated beast when, in 1961, Giovanni Micholotti
styled the TR4. Under the body however, it was still
essentially the original TR, though the evolutionary
process was now well under way.
The 1965 TR4A may have looked the same as the
TR4 but was transformed with a redeveloped chassis and
independent rear suspension. In the US, the new "bell"
chassis was modified lightly so that the older live rear axle
could continue in use. It had been felt that US drivers
would not be comfortable with the more sporting
characteristics of the new irs axle!
Two years later, the TR5 and TR250 was introduced
with its six cylinder 2.5 litre engine. Now much sought
after, the TR5 (and the TR250 of America) gave a new
lease of life to this enduring classic.
The TR5/250 didn't last long though. After only
fifteen months the TR5 and TR250 were replaced by the
TR6 in November 1968. Micholotti was unavailable to
design the TR6 body, busy on a number of projects and
so, after an exhaustive search, Karmann of West Germany
were selected to produce designs. The new TR6 used the
same chassis, inner shell, screen, and (if you look closely)
even the same doors. Stylish and understated, losing none
of the raw aggressiveness and purposeful design of the
earlier TR models, the new model was another
evolutionary step forward - retaining the best aspects of
the classic TR.
Wider wheels were used on the new model while
beneath the skin, the suspension geometry was revised
and an anti-roll bar was added. In 1970 revised wheel
trims were included, while inside the car a new steering
wheel was fitted and seat designs were improved to
protect against whiplash injuries.
1971 saw a new gearbox, taken from the new
Triumph Stag. Being much stronger than the previous
unit it was more able to deal with the powerful engine
that it had been mated to. The old "A" type overdrive unit
was replaced with the more durable "J" type, the only
negative point being that it operated on third
and forth gear only. Overdrive became standard fitment
In 1973 a front spoiler was added, wheel trims revised,
matt black wipers introduced - with revisions to
instruments and switches. New external badging was
provided. Wire wheels, rarely requested as an option, were
deleted in the same year. Seats were revised again and,
externally, new overriders were installed on USA models.
Throughout the development and production life of
the TR6 the corporate owners of Triumph, British
Leyland, were making changes affecting the whole
organisation. Triumph had run its own, albeit small,
competitions department until British Leyland gave
responsibility for a competitions programme to Peter
Browning of Abingdon's Competitions Department.
In the US, Kas Kastner headed up North American
efforts, and a canny, clever man he was too, knowing all
the wrinkles of the SCCA rule book inside out.
The SCCA, or more properly the Sports Car Club of
America, was the premier American racing
organisation. Kas' reputation for turning the
TRs into rocket ships had suffered setbacks with
the introduction of the TR5 which, with its
bigger, difficult to tune engine, was put in a
class with more predatory fish. However,
following the introduction of the TR6 Kas
discovered to his delight that a change in
the rules meant that he could run the new
TR6 with fuel injection. Better still he
could run any sort of fuel injectors with
With the original fuel injection system in
place but disconnected, Kas ran a modified
injector set up through the trumpets, blasting fuel
straight in and giving the engines a massive 255 bhp. It
provided a new lease of life on the tracks against
competition such as Porche, and battled manfully on for
a few more seasons to great success.
The last fuel injected TR6 left the Coventry factory in
July 1975, the last Federal version a year later. During this
time the new TR7 was introduced and the two models,
radically different in every way, were manufactured side
by side for a short while.
Some cars just refuse to lie down and the Triumph
TR6 is no exception. In the late 1980's Britain's great
export took on a star role in "Three Men and a Baby".
Triumph enthusiasts were buzzing with excitement
when, in 1992, British Motor Heritage re-introduced the
TR6 body shell. Undoubtably recognised as the last
"macho" British sportscar, the new shells, all
manufactured using original tooling and jigs, gave
Triumph's classic a new lease of life.
Re-introducing the TR6 shells was the culmination of
years of research and hard work, but on their own make
up only part of an amazing story. More parts are available
for the whole range of TR sports cars than ever before
thanks to the unstinting efforts of enthusiasts around the
world. Old tooling is continually being re-discovered and
used again to produce obsolete parts, while reproduction
components, often better than the originals (thanks to
modern material use) are arriving on the scene everyday.
Specialists around the world have bent all their thoughts
and skills to keeping these cars on the road and thanks to
their efforts the TR owner has back up and technical
support that almost defies equal. It would be hard to
imagine the owner of a TR ever having to scrap a car now.
The six cylinder TR engine
It's hard to believe that the six cylinder engine that
powered the TR5, TR250 and TR6 had its humble
beginnings in the 803cc Standard 8 of 1954. Harry
Webster's 4 cylinder engine was used in the Triumph
Herald, Spitfire and eventually even in the MG Midget,
having grown into a 1500cc engine. Along the way, the
engine gained two extra cylinders and, with a capacity of
1998cc, was used to power the Vanguard Six, Triumph
2000 and GT6 and, in reduced capacity initially, the
For TR use however, the engine needed even greater
performance and though the rally engined Triumph
2000s were getting 150 bhp out of triple Weber
carburated cars, this was at the cost of economy! The
whole family of engines on which the TR engine was
based used a stroke of 76mm. The only way forward was
to increase the stroke to 95mm - flying in the face of
modern engine design at the time. To do this, the block
was extensively modified to take a new crankshaft. At the
same time, the cylinder head was completely redeveloped.
With a slightly wild camshaft, the new fuel injected
engine gave 150bhp. The carburetted "Federal" version
offered 104bhp. The Lucas fuel injected cars were given
an engine prefix of CP, the carburetted versions had a
prefix CC. In 1973, with the introduction of a milder
cam (to improve TR performance in heavy traffic), the
prefixes changed from CP to CR and CC to CF.
The fuel injected cars maintained a compression ratio
of 9.5:1, though the Federal cars began life with a ratio of
8.6:1, reducing to 7.75:1 in 1971 (coupled to new
Stromberg 175 CDSE(2) carburetters) and then to 7.5:1
in 1973 (this time with Stromberg 175 SEV carburetters
Exhaust and emission restrictions gradually stifled the
performance of Federal/Californian cars eventually to
TR4 standards. Even so sales of the cars continued
alongside the newly introduced TR7.