WARNING When   compressing   any   suspension system  spring,   be   extremely   careful   to position  the  spring  compressor  properly..  If the spring were to pop out of the compressor, serious  injuries  or  death  could  result. With   the   coil   spring   and   upper   damper   unit removed, you can now remove the shock cartridge. A new shock cartridge can be installed in the strut outer housing to restore the strut to perfect condition. Some manufacturers   recommend   that   the   strut   shock absorber  be  rebuilt  once  the  strut  shock  absorber  is repaired or replaced. The strut can be reassembled and installed in reverse order of disassembly,. NOTE For  exact  procedures  for  the  removal, repair,  and  installation  of  a  strut  assembly, refer to the manufacturer’s service manual. Spring Service Springs  require  very  little  periodic  service.  Leaf spring  service  usually  involves  bushing  replacement. Torsion  bars  require  adjustment  and  coil  springs require no periodic service. Spring  service  requirements  can  be  found  in  the service manual of the vehicle you are working on. Spring   fatigue   (weakening)   can   occur   after prolonged service. The fatigue lowers the height of the vehicle, allowing the body to settle toward the axles. This  settling  or  sagging  changes  the  position  of  the control arms, resulting in misalignment of the wheels. This condition also affects the ride and appearance of the vehicle. To   check   spring   condition   or   torsion   bar adjustment, measure CURB HEIGHT (distance from a point on the vehicle to the ground). Place the vehicle on a  level  surface.  Then  measure  from  a  service  manual specified point on the frame, body. or suspension down to  the  shop  floor.  Compare  the  measurement  to  the specifications in the service manual. If the curb height is  too  low  (measurement  too  small).  replace  the fatigued springs or adjust the torsion bar. NOTE For  instructions  on  the  removal  and installation  of  springs.  refer  to  the  manu- facturer’s service manual. The  vehicle  should  also  be  at  CURB  WEIGHT when checking spring condition and curb height. Curb weight is generally the total weight of the vehicle with a  full  tank  of  fuel  and  no  passengers  or  cargo.  Also, make  sure  nothing  is  in  the  passenger  compartment that could possibly increase curb weight. Curb weight is given in pounds or kilograms. Q1. Q2. Q3. Q4. Q5. Q6. Q7. Q8. REVIEW  2  QUESTIONS What   component   of   the   suspension   system prevents  the  control  arm  from  swinging  to  the front or rear of the vehicle? In the suspension system, what is the function of the  stabilizer  bar? At  what  location  on  the  control  am  is  the  ball joint  attached? What is the most common type of shock absorber used on modern vehicles? On  a  vehicle  that  uses  struts  on  the  front,  the struts replace what suspension component? What  term  is  used  to  describe  the  stiffness  or tension of a spring? The radial play of a ball joint can be checked by  moving  the  wheel  straight  up  and  down. (T/F) What tool is required to remove the coil spring form the strut? STEERING  SYSTEM Learning  Objective:  Identify  the  major  components of a steering system. Explain the operating principles of steering systems. Describe the differences between the  linkage  and  rack  and  pinion  type  steering. Describe  the  operation  of  power  steering.  Describe service and repair procedures for manual and rack and pinion type steering mechanisms. Explain the service procedures  for  servicing  power  steering  belts,  hoses, and fluid. The  steering  system  allows  the  operator  to  guide the  vehicle  along  the  road  and  turn  left  or  right  as desired. The system includes the steering wheel, which the  operator  controls,  the  steering  mechanism,  which changes  the  rotary  motion  of  the  steering  wheel  into straight-line  motion,  and  the  steering  linkage.  Most systems  were  manual  until  a  few  years  ago.  Then power steering became popular. It is now installed in most   vehicles   manufactured   today.   The   steering 8-16