Triumph Tr6 MOT Failures

An analysis of 10,455 real DVSA MOT tests on the Triumph Tr6 — what fails, how often, and how that compares to every other car on UK roads. Generations covered: TR6 (1968–1976).

Where the Triumph Tr6 fails its MOT

The single biggest MOT failure point on the Triumph Tr6 is wheel bearings worn — this model is 58 times more likely to fail on this item than the average car on UK roads. That makes it a major concern for anyone buying or owning this model. Across 10,455 MOT tests, 15.22% of all Triumph Tr6 tests recorded this as a failure.

Suspension failures typically mean worn bushes, drop links, or dampers. These affect handling and tyre wear. Budget £150–£400 per corner at an independent garage for full suspension overhaul.

Other notable weak points include fluid leak (28x the fleet average), steering rack wear (178x the fleet average), electrical wiring fault (20x the fleet average), and excessive radial movement between the top of th... (110x the fleet average). These ratios compare the Triumph Tr6's failure rate on each item against the national average for all cars tested — a ratio of 10x means this model fails ten times more often than a typical car.

The failures span 5 categories: Suspension, Exhaust & Emissions, Steering, Lights & Electrics, Wipers & Windscreen. If you're inspecting a Triumph Tr6 before purchase, these are the areas to focus on — and if any have been flagged as advisories on a previous MOT, they're likely to become failures in the near future.

How failures change with mileage

The Triumph Tr6's weak points shift as the car covers more miles. Understanding these patterns helps you know what to expect — and what to budget for — at each stage of ownership.

Under 60,000 miles

At this mileage, most failures are either design-related or caused by age rather than wear. Components like bushes and drop links may not have been replaced yet, and original-fit parts can deteriorate even on low-mileage cars that spend a lot of time sitting.

For the Triumph Tr6 specifically, the DVSA data shows the most common failures at this mileage are excessive radial movement between the top of th... (110x the average) and steering rack wear (55x). wheel bearings worn (50x) and fluid leak (28x) also appear frequently.

60,000 to 100,000 miles

This is where routine wear items start to show up. Brake components, tyres, and exhaust parts have done serious work by this point. Cars that have been well serviced will show fewer of these failures — this mileage band is where good maintenance really separates the well-kept from the neglected.

For the Triumph Tr6 specifically, the DVSA data shows the most common failures at this mileage are electrical wiring fault (15x the average) and light unit fault (12x). wheel bearings worn (12x) and fluid leak (5.5x) also appear frequently.

The shift from excessive radial movement between the top of th... at lower mileages to electrical wiring fault at higher mileages is typical — early failures tend to be design or factory-related, while high-mileage failures reflect accumulated mechanical wear. A car that's been well maintained will usually dodge the worst of both.

Known issues beyond the MOT

An MOT only tests roadworthiness at a single point in time — it won't catch developing faults, intermittent problems, or issues that haven't yet reached the failure threshold. These are the issues that Triumph Tr6 specialists and owners flag most frequently, drawn from manufacturer technical bulletins, workshop data, and verified owner reports.

Chassis rust (TR6) Dangerous

The TR6 uses a separate steel chassis with substantial side rails and cross-members that support the entire vehicle structure. Affects TR6; typical independent garage repair cost is £1,000–£3,000.

Wheel bearing failure (TR6) Dangerous

The TR6 rear wheel bearings are large ball races housed in the rear hub carriers, with the differential drive flanges bolted to the hub assembly. Affects TR6; typical independent garage repair cost is £200–£400.

Differential noise (TR6) Major

The TR6 rear differential is a Salisbury unit with crown wheel and pinion gears that are prone to wear, particularly when oil levels drop or contamination occurs. Affects TR6; typical independent garage repair cost is £400–£800.

Brake binding (TR6) Major

The TR6 front disc brake system uses single-piston Girling calipers that are vulnerable to piston seizure and slider pin corrosion. Affects TR6; typical independent garage repair cost is £150–£300.

For the complete picture — including repair costs across independent, specialist, and dealer garages — see the full Triumph Tr6 common problems breakdown.

What to check before buying a Triumph Tr6

Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Triumph Tr6:

Suspension — check for wheel bearings worn, suspension joint dust cover severely deteriorated. Exhaust & Emissions — check for fluid leak. Steering — check for steering rack wear, excessive radial movement between the top of th.... Lights & Electrics — check for electrical wiring fault, light unit fault.

Beyond the MOT items, ask specifically about chassis rust and wheel bearing failure. These won't show up on a standard MOT but can be expensive to fix — repairs start from £1,000. A specialist pre-purchase inspection is worth the investment on this model.

Always check the car's full MOT history for patterns — recurring advisories often become failures within 12 months. And verify the service history to confirm maintenance has been kept up to schedule. Enter any reg into our free car check to see the complete picture.

MOT failure data sourced from DVSA bulk test records via data.gov.uk. Ratios compare this model's failure rate against the national fleet average. Known issues sourced from manufacturer bulletins, specialist workshops, and verified owner reports.