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2.4 Rear Suspension & Wheel bearings
|Information||Method of Inspection||Reason for rejection|
|A: All Suspension Types|
need not be fitted with rear suspension: some customised machines
take advantage of this on the rear suspension, eg 'chopper'
or 'lowrider' motorcycles.It is important to distinguish between
play in the rear suspension bearings and that in the wheel bearings.
Light rubbing contact between the body and shroud of a shock absorber is acceptable.
Shock absorbers fitted to the rear of some small machines may have limited damping.
It may be necessary to remove side panels or remove the seat to carry out a full examination (intro item 4).
If no centre stand is fitted, care should be taken when Jacking the machine. It may be desirable to use an assistant.
With mono-shock type suspension some
linkage movement may be observed when the suspension is in an abnormal position.
If twin shock absorbers are fitted the machines presenter should be informed if it appears they are not equally adjusted,
ALL SUSPENSION TYPES
a. Check the condition, security and alignment of the rear suspension components.
b. Check condition of suspension springs
c. Check shock absorbers for oil leakage due to seal failure
2. With the rear wheel clear of the ground:
a. look for play in the suspension bearings or bushes by attempting to move the suspension from side to side and up and down;
b. ensure that the wheel, it's fixings and locking devices are present and secure and check the wheel bearings for tightness or play;
c. spin the wheel and listen for roughness in the bearings
d. Check condition of suspension with regard to corrosion, distortion and modifications.
3. With the rear wheel on the ground
observe the amount of movement and the effectiveness and security of the shock absorbers by sitting on the machine and depressing the rear suspension several times as far as possible.
a rear suspension component which is:
a. loose, cracked, excessively bent, misaligned or excessively corroded
b. A road spring, (see information column.)
(i) incomplete, cracked or fractured;
(ii) worn or corroded so that it's cross sectional area is reduced such that it is seriously weakened;
(iii) repaired by welding.
c. Oil leakage indicating failure of the seal.
(i) Excessive free play or deterioration in bearing or bush. (see information column).
(ii) a seized component-
b. a loose wheel spindle or securing nut(s) or locking device missing or insecure.
c. excessive tightness or free play in the wheel bearings, excessive roughness in a wheel bearing whilst the wheel is rotating indicating early failure is likely
d.deliberate modification which significantly reduces the original strength, excessive corrosion, severe distortion, a fracture or an inadequate repair of a load bearing member or its supporting structure
a. fouling between fixed and moving parts which affects the movement of the rear suspension. (See information column)
b. excessive stiffness in the movement of the rear suspension. A shock absorber with inadequate damping effect or insecurely mounted (see information column)
|B: Mono Shock Type Suspension|
Mono-shock type suspension
4. On machines fitted with mono-shock type suspension, check as far as possible the condition of pivot points for wear and security (See information column)
|4. Seizure excessive wear or insecurity at a pivot point.|
|Issue Date: June 2002|
Reproduced from the MOT Inspection Manual by kind permission of THE VEHICLE INSPECTORATE.