MOT Suspension

image: car suspension

Under the bonnet checks

  • Upper suspension joints, including securing nuts/bolts
  • Any other suspension components which can be inspected from beneath the bonnet

Under the vehicle checks

Applies to the front and rear suspension

  • No split pins or nuts missing, no components broken or excessively damaged
  • Road springs are checked for condition and completeness
  • All suspension joints are checked for condition and play
  • Ball joint dust covers are checked for splitting and not allowing the ingress of dirt etc
  • Shock absorbers must not leak and must be secure
  • Inappropriate repair or modification or excessive heat applied to any suspension components
  • Any drive shaft (except the prop shaft) support bearing excessively worn or coupling gaiter missing or split and no longer preventing the ingress of dirt etc.

The suspension is checked for wear by the assistant applying loads in various ways with the wheels jacked up whilst the Tester observes the result from beneath the vehicle. This may include the use of approved wheel play detectors in some Test Stations.

Please note: There are a number of different suspension systems, and the specific examination will depend on the design of the suspension system.

How to test your shock absorbers

Shock absorbers are relatively uncomplicated, but there role should not be underestimated. Try this simple ‘bounce’ test. Press down on one corner on your car and let go. Count the number of bounces before the car comes to a rest, repeat on the other three corners. If the car bounces twice then your shock absorbers may have reached the end of their life. The most common fault is fluid leak, without adequate hydraulic fluid the shock absorber is not able to dampen the bouncing spring. This may lead to suspension malfunction, abnormal tyre wear or a knocking noise.

If you have a faulty power steering rack or expensive steering pumps to replace. Just change the steering rack for a standard one for the same vehicle model and year. As long as the steering is not adversely affected by this will be fine, the tester may need to give your car a road test to make sure that the tester is happy with it.