Triumph TR7 Buyers Guide

The TR7 has no separate chassis: its steel body is the structure, so the body comes first. No club or magazine list of the TR7's own rust points was among the sources read; a club or a specialist can show where to look on a particular car. What the sources do say:

• The Canley cars, from October 1978, were given an anti-chip coating, Motor Sport reported, and the magazine was frank about the steelwork of its 1979 car: "Some of the detail sheet steel work is pretty abysmal."

• A convertible's stiffness depends on the box section behind the seats and on rear quarter panels extended down to join the sills (rocker panels), which Triumph added when it took the roof away; its front bumper carries tuned weights to damp the shake of an open body.

• Large sunroofs, offered as options, took "a serious toll on the rigidity", Ate Up With Motor writes.

• Many TRs have come back to Britain from America. Not all of them lived in dry states, the TR Register warns, and their corrosion can be "just as severe" as a home-market car's; every American car was left-hand drive, so a right-hand-drive one has been converted.⁠source 4​source 5​source 6​source 1​source 7

The engine is sound at heart, and its weaknesses are well known. Godrich puts it in a sentence:

The aluminium head sits on an iron block, and overheating, which the early cars were known for, can blow the head gasket and warp the head.

The distributor is at the back of the engine and hard to reach, and the car's long nose defeats many hired engine cranes; Godrich suggests dropping the engine out with its subframe instead.⁠source 2​source 1​source 3​source 5

The early cars' four-speed gearbox (transmission) gave way in 1978 to the Rover SD1's five-speed, which Simon Godrich's checklist calls the more robust unit. The five-speed baulks when cold: Triumph changed its recommended oil from a hypoid gear oil to automatic transmission fluid. It also has an internal oil pump, so the TR Register warns against towing a car far on its rear wheels with the propshaft in place.

Brakes were the TR7's weak point from new. Motor Sport complained of them in 1976 and again in 1979, and Godrich is blunt:

At the back, the self-adjusters seize, and a car can fail its MOT test on them. The suspension was soft as standard: look for tired dampers, worn bushes on the rear trailing arms, which cause bump steer, and worn subframe and anti-roll-bar mountings. A wobble in the steering at 80 to 100 km/h (50 to 60 mph) is a common complaint, the TR Register notes, with many possible causes, from the discs and the geometry to a worn rack. The clutch's pivot pin can wear through its fork, and clutches stick after a car has stood.

Of the pop-up headlamps, Godrich is blunt:

The causes Godrich names are the connections under the front wings (fenders), poor earths and the Pektron control unit. The earths themselves, two at the front of the engine bay, two on each rear lamp cluster and one inside the windscreen (windshield) pillar, cause many electrical faults, and indicators that glow without flashing usually mean a bad earth. The heater matrix leaks into the footwell when its seals perish, and replacing it means taking the dashboard out. The seats were trimmed in black at first, then tartan from March 1977, plaid at Canley and, by Wikipedia's account of Bill Piggott's guide, velour at Solihull; an original interior is worth checking against the year.⁠source 2​source 3​source 8​source 5​source 9​source 1

The convertible looked better than the coupé to Road & Track, and Motor Sport found less boom in it; the five-speed cars were better geared and stronger. British and European cars had more power than the American cars, which had a federal engine. Where a car was built can be read from its number, which identification decodes; many writers say the Canley and Solihull cars were better made, but that is an opinion, and where the TR7 was made gives both sides. Judge the car, not the factory.

The rarer cars need their numbers checked. A TR7 Sprint is proved only by its commission and engine numbers, which identification sets out; anything else with a 16-valve head is a conversion, and conversions are many. So are V8s: Ate Up With Motor writes that the survivors include "an abundance of Sprint and V8 conversions". A Spider's livery can be copied with decals, and the "Jubilee" rests on one caption; special editions explains each. A Heritage Certificate from the British Motor Museum gives a car's original specification from the factory's records, and the TR Register advises matching the commission number on the plate to the V5 and asking the club's registrar.