Nothing about dates.....MOT inspection manual fit for purpose and visual inspection
Section 5 Axles, wheels, tyres and suspension
5.2 Wheels and tyres
5.2.1 Road wheel and hub
Defect Category
A wheel:
with a loose or missing wheel nut, bolt or stud
Major
with more than one loose or missing wheel nut, bolt or stud
Dangerous
A spigot mounted wheel hub:
excessively worn or damaged
Major
worn or damaged to the extent that wheel security is adversely affected
Dangerous
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5.2.2 Road wheel condition
You only need to inspect the road wheels fitted to the vehicle at the time of the inspection. If you notice a defect on a spare wheel, you should tell the vehicle presenter about it.
You mustn’t remove wheel hub caps.
You can accept abutting ends on detachable spring retaining rings on wheel rims of semi-drop centre type (identified by the ends of the ring shaped to interlock) as long as the retainer is adequately and safely located in the wheel rim.
Defect Category
Any fracture or welding defect on a wheel
Dangerous
A tyre retaining ring:
not correctly fitted
Major
likely to come off
Dangerous
A wheel:
badly distorted or wear between wheel and hub at spigot mounting
Major
distorted or worn to the extent the wheel or tyre is likely to become detached
Dangerous
A wheel and its fixings not compatible
Major
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5.2.3 Tyres
Size
The aspect ratio of a tyre is included in the size marking. For example, a 215/55R15 has an aspect ratio of 55%.
'Standard' car tyres have a nominal aspect ratio of 82% (unless marked otherwise) and these are almost identical in size to tyres with an aspect ratio of 80%. They can be safely mixed in any configuration on a vehicle.
Some tyres may be marked with two sizes. For example, a 185/75R14 tyre may be dual marked 185R14. In such case you can accept either marking.
Load rating – Classes 5 and 7 only
A tyre load rating table is in Appendix B.
Make sure the tyre load rating is suitable for the axle weight.
You can find the permitted maximum laden weight of an axle on the manufacturer’s plate.
If axle weights aren’t displayed on the manufacturer’s plate, you must assume that the load capacity of the tyres are suitable, unless there’s indisputable evidence to suggest otherwise.
If a goods vehicle has a ‘Ministry’ plate showing lower axle weights not to be exceeded in Great Britain, you must use those instead of the ones on the manufacturer’s plate.
Speed rating – Classes 5 and 7 only
A tyre's speed rating is shown on the sidewall as a letter and usually precedes or follows the load rating. Speed ratings from A to K are unacceptable, with the exception of H.
If no speed rating is shown it must be assumed that the minimum requirements are met.
Load ratings for low speed rated tyres – Class 5 vehicles only
Tyres must be suitable for use up to 70mph (L speed rating) unless the vehicle is a 'restricted speed vehicle'.
If the tyre can carry the maximum permitted axle weight of the vehicle, these vehicles can use tyres with a lower speed rating tyres up to 70mph as follows:
K speed rating – but the tyre's carrying capacity is reduced by 3%
J speed rating – but the tyre's carrying capacity is reduced by 7%
For example, K speed rating tyres can be used at 70mph if the load is reduced as follows:
146/143K = 6,000kg single or 10,900kg dual - less 3% = 5,820kg single or 10,580kg dual
You mustn’t accept a tyre load rating that’s less than the maximum permitted axle weight.
Structure
Tyres of different types of structure, such as radial-ply and cross-ply, mustn’t be mixed on the same axle.
Steel and fabric radial-ply tyres are considered to be the same structure.
Run flat and conventional tyres can be mixed on the same axle, although this isn’t recommended.
Condition and fitment
Evidence of a tyre contacting a part of the vehicle, such as due to tyre flexing or suspension movement, isn’t considered to be a defect. A vehicle should only be rejected if the tyre is fouling a part of the vehicle at the time of test.
Some vehicles have lock stops comprising rubbing pads on the body that the front tyres may contact on a full lock. These are acceptable if they are properly maintained so that they don’t damage the tyres.
You can use a blunt instrument to open a cut in the tyre to check for exposed ply or cord as long as you don't cause further damage.
When assessing cuts in a tyre, it is permissible to check whether a cut is deep enough to reach the play or cord by using a blunt instrument to open the cut taking care not to cause further damage.
The following criteria should be used when assessing a cut in a tyre:
any ply or cord that can be seen without touching the tyre – fail
if by folding back rubber or opening a cut with a blunt instrument, so as not to cause further damage, exposed ply or cord can be seen irrespective of the size of the cut – fail
if a cut which is more than 25mm or 10% of the section width whichever is the greater, is opened with a blunt instrument and cords can be felt but not seen – fail
Before failing a cut, you must make sure it's the cords that you can feel not a foreign object. If you're not sure, then you should pass and advise.
When assessing lumps or bulges in a radial ply tyre, care should be taken to distinguish between normal undulations in the carcass, resulting from manufacturing, and lumps or bulges caused by structural deterioration.
Take extra care with stretched tyres because they're more prone to sidewall damage.
Recut tyres are only permitted on:
vehicles over 3,050kg ULW
goods vehicles with an ULW of at least 2,540kg having at least 16 inch (405mm) diameter wheels
passenger vehicles with an ULW of at least 2,540kg having 8 or more passenger seats
You should only accept tyres with NHS, Not for Highway Use or similar markings if they have an ‘E’ marking and a number contained within a circle. Adjacent to this circle, the sidewall must also be marked with a six digit number, which may be preceded by 75R or similar marking (see example below).
Example of a tyre marking
Direction of rotation may be indicated by an arrow and/or words, but an arrow by itself should not be taken to indicate direction of rotation.
Tread depth
A tread pattern is the combination of plain surfaces and grooves extending across the breadth of the tread and round the entire circumference. It excludes any tie-bars, tread wear indicators, or features designed to wear out substantially before the remainder of the pattern, and other minor features.
In simple terms, grooves containing tread wear indicators (TWI) or grooves cut as deep as those containing the wear indicators when new, are considered to be primary grooves. Other grooves or sipes that aren't cut as deep as the primary grooves are secondary grooves and aren't to be considered when assessing tread depth.
The ‘breadth of tread’ is the part of the tyre which can contact the road under normal conditions of use measured at 90 degrees to the peripheral line of the tread.
Different vehicles require different tread depths.
The following vehicles first used on or after 3 January 1933 need 1.6mm tread depth:
passenger vehicles with a maximum of 8 passenger seats, excluding the driver’s seat
goods vehicles or dual-purpose vehicles not exceeding 3,500kg DGW
tricycles with an ULW more than 410kg and all quadricycles
The primary grooves of the tread pattern must be at least 1.6mm deep within the central three-quarters of the breadth of tread and around the entire outer circumference of the tyre (see diagram 1).
Either side of the central three-quarters of the tyre can be devoid of tread (‘bald’).
Diagram 1. Primary and secondary grooves in tyre tread pattern
Diagram 1. Primary and secondary grooves in tyre tread pattern
The following vehicles must have 1.0mm tread depth:
vehicles first used before 3 January 1933
passenger vehicles with more than 8 passenger seats excluding the driver’s seat
tricycles with an ULW not exceeding 410kg with an engine capacity greater than 50cc
The tread pattern must be visible over the whole tread area (see diagram 2), and have a depth of at least 1.0mm throughout a single band of at least three-quarters over any section of the breadth of tread round the entire outer circumference of the tyre.
The 1.0mm tread depth requirement applies to the whole tread width if the original tread pattern didn’t extend beyond three-quarters of the tyre width when new.
Diagram 2. Tread pattern visibility
Diagram 2. Tread pattern visibility
Tyre pressure monitoring system (TPMS)
The inspection of the tyre pressure monitoring system (TPMS) is for M1 vehicles first used on or after 1 January 2012.
The TPMS warning lamp (see diagram 3) can operate in many ways depending on the vehicle type. You must only reject vehicles if it's clear that the lamp indicates a system malfunction and not simply indicating that one or more of the tyre pressures is low.
Diagram 3. Example of a TPMS warning lamp
Diagram 3. Example of a TPMS warning lamp
Defect Category
A tyre:
load capacity or speed rating not in accordance with the minimum requirements
Major
load capacity insufficient for axle presented weight
Dangerous
Tyres on the same axle or on twin wheels are different sizes
Major
Tyres on the same axle of different structure
Major
A tyre:
with a cut in excess of the requirements deep enough to reach the ply or cords
Major
with a lump, bulge or tear caused by separation or partial failure of its structure, including any lifting of the tread rubber or with cords exposed or damaged
Dangerous
Tyre tread depth not in accordance with the requirements
Dangerous
A tyre fouling a part of the vehicle
Major
A recut tyre fitted to a vehicle not permitted to be fitted with recut tyres
Major
Tyre pressure monitoring system:
malfunctioning or tyre obviously under-inflated
Minor
obviously inoperative
Major
A tyre not fitted in compliance with the manufacturer’s sidewall instructions
Major
A tyre valve seriously damaged or misaligned likely to cause sudden deflation of the tyre
Dangerous
A tyre incorrectly seated on the wheel rim
Major
