Module 7A8

1. Module 7A8 Diagnose Short Arm/Long Arm Front Suspension Problems

2. Part Function - Control Arm • Link between frame and steering knuckle • Arm bushings provide swivel joint • Different lengths of arms keep tire in alignment when going up and down • Has rubber bumpers to prevent metal contact on rough roads

3. Part Function - Steering Knuckle • Link between control arms and wheel • Ball joints swivel to allow movement

4. Part Function - Coil Spring • Connected between lower control arm and frame • Keeps tire in contact with road • Absorbs energy from road shock

5. Part Function - Shock Absorber • Dampens spring movement • Stabilizes wheel contact with road • Uses hydraulic oil to dampen vibrations

6. Part Function - Stabilizer Bar • Connects right and left control arms • Supported by frame • Reduces body roll on corners • Also called sway bar

7. Part Function - Stabilizer Link • Connects each end of the stabilizer to the lower control arm • Provides flexible motion

8. Part Function - Torsion Bar • May be used instead of springs • Adjustable to control vehicle height

9. Performance Problem Causes and Diagnosis - Noises • Loose mountings • Loose or damaged shocks • Mispositioned coil spring • Worn or damaged ball joints • Worn control arm or stabilizer bushings

10. Performance Problem Causes and Diagnosis - Ride Height • Damaged or broken parts • Broken or fatigued springs • Misadjusted torsion bar

11. Performance Problem Causes and Diagnosis - Body Roll • Bad shocks • Worn stabilizers • Worn control arm bushings • Worn ball joints

12. Parts Inspection - Control Arms • Raise vehicle, inspect for signs of damage • Lift wheel up and down for ball joint wear • Use pry bar to inspect for arm bushing movement

13. Parts Inspection - Steering Knuckle • Check for damage

14. Parts Inspection - Coil Spring or Torsion Bar • Check for cracks and proper mounting

15. Parts Inspection - Shock Absorbers • Check for leaks, bent piston rod • Check attaching bolts • Bounce car, then count number of rebounds • A good shock will stop on three or less rebounds

16. Parts Inspection - Stabilizer Bar • Check for broken or worn bushings, parts • Check mounting points

17. Parts Maintenance - Cleaning • Usually not needed

18. Parts Maintenance - Check Connections • Tighten bolts • Check spring seating • Check ball joints • Check stabilizer

19. Parts Maintenance - Lubrication • Follow Mfgs. Schedule • Lube when grease fittings are present

20. Parts Repair - Suspension Parts Not Repairable • Safety • Cost • Performance

21. Parts Repair - Front End Alignment • Needed after control arms, coil spring, and steering knuckle replaced • Not needed after shock or stabilizer bar replacement

22. Parts Replacement - Stabilizer Bar • Raise and support vehicle • Remove stabilizer links, mounting brackets, and bushings • Reassemble with new parts and torque to manufactures specs.

23. Parts Replacement - Shock Absorber • Remove upper shock nut • Raise and support vehicle • Remove lower shock mounting and remove shock • Install new shock and tighten to manufacture specs.

24. Parts Replacement - Upper Control Arm • Raise and support vehicle • Remove wheel and support lower control arm • Remove upper control arm ball joint • Remove and mark alignment shims, remove mounting bolts • Replace ball joint, bushings • Install new part

25. Parts Replacement - Coil Spring • Raise and support vehicle • Remove wheel and support lower control arm • Remove shock and stabilizer link • Cage coil spring • Remove lower control arm and ball joint • Remove and replace spring, control arm

26. Parts Replacement - Lower Control Arm • Similar procedure to removing coil spring

27. That Concludes Module 7A8