← Lessons 13-Planned Preventive Maintenance Quiz 0 / 12 read 1. INTRODUCTION 2. THE IMPORTANCE OF PLANNED MAINTENANCE 3. PROGRAMME PLANNING 4. PROGRAMME OBJECTIVE 5. THE SYSTEM AND PROCEDURE 6. IN-HOUSE MAINTENANCE 7. CONTRACTED OUT MAINTENANCE 8. DOCUMENTATION 9. ELECTRONIC RECORD KEEPING 10. CONCLUSION QUICK EXAM NUMBERS / FACTS – MEMORISE THESE 12. FINAL MEMORY CHECKLIST QUICK EXAM NUMBERS / FACTS – MEMORISE THESE 15 months – record-retention period stated in the material. PG9 – prohibition notice. 10 years – the steered-axle tyre age limit stated. 6 mm – tread depth for goods vehicles up to and including 3,500 kg GVW, in the specified band. 1 mm – tread groove depth for vehicles over 3,500 kg GVW, in the specified band. 3,500 kg – mirror threshold for close-proximity and wide-angle mirrors. 7,500 kg – threshold for the additional front-view mirror. 120,000 km/year – example of general-haulage distance linked to a maximum 6-week interval. 6 weeks – example maximum interval above; also the stated interval for vehicles 12 years or older. 28 days – notification period when increasing beyond the operator licence interval or changing maintenance provider. 6 months – forward planning period for inspection and servicing dates. 1,020 kg – trailer unladen-weight threshold stated for the annual-test requirement with powered braking. 2 years – digital tachograph recalibration and GV60 renewal periods stated. 6 years – analogue tachograph recalibration and ATP validity stated. 6 years maximum – ADR tanker certificate validity stated. 5 years maximum – livestock vehicle approval validity stated for journeys over 8 hours.