Triumph TR7 Parts
Much of the TR7 came from other British Leyland cars, the Dolomite and the Rover SD1, and much of it went on into the TR8, which still helps owners. What interchanges, which wheels fit, the upgrades and conversions owners make, and the clubs that keep the cars' records.
The TR7 was built from British Leyland's shelves. Its engine family, its first gearbox and its first axle came from the Triumph Dolomite saloon (sedan), its later gearbox and axle from the Rover SD1, and the TR8 shared the TR7's body and most of its interior. This page says what interchanges and what owners commonly change.source 1source 2
Shared parts
The slant-four was the Dolomite family's engine. Motor Sport reported in 1975 that the TR7 used the block of the 16-valve Dolomite Sprint with the eight-valve head of the 1,854 cc Dolomite, and the first four-speed gearbox (transmission) and the rear axle came from the Dolomite too. The four-speed's ancestry goes further back: the TR Drivers Club calls it derived from the Marina's and the Dolomite's, and AROnline from the Morris Marina's.
The later cars took their gearbox and axle from the Rover SD1: the SD1's five-speed was standard from the move to Canley in 1978, and with it came an axle of the SD1's type, Motor Sport reported. The TR8 differed underneath: Ate Up With Motor notes its stiffer springs, different damping, thicker front discs and a front subframe of its own. The specifications give each gearbox's ratios.source 1source 2source 3source 4source 5
Competition parts
In 1978 Leyland ST, the competitions department at Abingdon that ran the works rally cars, offered a range of parts for the four-cylinder TR7, and Motor Sport summed it up:
All the major aspects of the four-cylinder TR7 are catered for up to a full competition standard, including the components of the five-speed SD1 gearbox which might make a useful alternative to the expensive ZF one day.
No source read lists the parts themselves or says what became of the stock.source 6
Wheels
The TR Register's guide gives the wheel fitments, and the specifications page gives the stud pattern and offset. Montego and Maestro alloys fit; MGF wheels, at ET20, may need spacers. Wheels from 356 to 432 mm (14 to 17 in) across can be fitted, but rims 178 mm (7 in) wide may foul.source 7
Common upgrades
Simon Godrich's checklist for the TR Drivers Club recommends electronic ignition, braided brake hoses and halogen headlamps, using the same kit as early MGBs. It notes uprated springs and dampers, which the club's editor recommends, and kits for four-pot calipers with ventilated discs, which may need 356 mm (14 in) wheels to clear them, and says that many owners fit uprated bushes. The buyers guide says what is wrong with the standard brakes.source 3
Conversions
Many of the TR7s that survive have been given the Dolomite Sprint's 16-valve head or Rover's V8, Ate Up With Motor writes. A 16-valve car is not a TR7 Sprint unless its numbers say so, as identification explains. V8 conversions will be covered on the TR8's site, triumph-tr8.com.source 5
Clubs
In Britain there are the TR Drivers Club, whose honorary president was Harris Mann, and the TR Register, which keeps registrars for the models. In America there are the Triumph Wedge Owners Association, which grew out of the TR8 Car Club of America, and the Vintage Triumph Register.source 8source 9source 10source 11
Sources
Every source the site cites is on the sources page.
- Primarymade at the time, by the maker or by people who were there
- Referenceserious later work: clubs, specialists, magazines, books
- Clive Richardson ("C.R."), "The TR7 makes a quiet British bow", Motor Sport, Feb 1975, p. 30, p. 30, the Dolomite's engine, gearbox and axle; p. 30, the Dolomite Sprint's block and the 1,854 cc car's head; the Dolomite's gearbox and axle. motorsportmagazine.com/archive/article/february-1975/30/the-tr7-makesa-quiet-british-bow Primary
- Clive Richardson ("C.R."), "The Triumph TR7", Motor Sport, Jun 1979, p. 58, p. 58, the SD1's five-speed and axle; p. 58, the SD1's five-speed and axle at Canley. motorsportmagazine.com/archive/article/june-1979/58/the-triumph-tr7 Primary
- Simon Godrich, "TR7 Tribulations" (owner's checklist), TR Drivers Club, the four-speed, Marina and Dolomite derived; the upgrades: ignition, brakes, hoses, suspension, headlamps. trdrivers.com/articles21/tr7tribulations1.html Reference
- Keith Adams, "The Cars: Triumph TR7/TR8 development story", AROnline, updated 8 Feb 2024, the four-speed, developed from the Marina's. aronline.co.uk/cars/triumph/tr7-tr8/bullet-development-story Reference
- Aaron Severson, "Way of the Wedge: The Triumph TR7 and TR8", Ate Up With Motor, 5 Feb 2012, pp. 1–5, p. 4, what the TR8 shared and what it did not; p. 5, the Sprint and V8 conversions among the survivors. ateupwithmotor.com/model-histories/triumph-tr7-tr8 Reference
- Motor Sport, News, editorials and short items on the TR7 (group), Jul 1975 – Aug 1981; Apr 2002, Sep 1978, Leyland ST's parts, "All the major aspects of the four-cylinder TR7 …". motorsportmagazine.com/archive Primary
- Malcolm Paris (compiler), "Triumph TR7 / TR7 V8 and TR8 Buyers Guide", TR Register, FAQ: the stud pattern, offset and centring; Montego, Maestro and MGF wheels; sizes and widths; the gearbox oil. tr-register.co.uk/resources/buyers-guide/triumph-tr7-tr8 Reference
- TR Drivers Club, Harris Mann Prints, the club's honorary president. trdrivers.com/harrismann21.html Reference
- TR Register, TR Register (UK club), home page, the TR Register and its registrars. tr-register.co.uk Reference
- Triumph Wedge Owners Association, "The Club", grown out of the TR8 Car Club of America. triumphwedgeowners.org/the-club Reference
- Vintage Triumph Register, "TR8", with the buyer's guides page, the Vintage Triumph Register. vintagetriumphregister.org/tr8 Reference