UNDERVEHICLE MAINTENANCE

1
UNDERVEHICLEMAINTENANCE

• Visual Inspection is a good place to start.
• Leaks are a warning of things to come.
• Everything under the chassis will eventually stop
  your car if they fail.
• Preventative maintenance goes a long way!!!!!

JH
2
TIRES

• TIRE STRUCTURE
• MAIN ELEMENT IS STEEL WIRE BEADS
• TIRE CARCASS OR CASING
• PLIES AND BELTS
• TREAD (RIBS AND GROOVES)
• INNER LINER

3
TIRE DESIGN

• THREE BASIC CONSTRUCTION DESIGNS
• BIAS
• BELTED RADIAL
• BELTED BIAS
• FOOTPRINT CONTROLLED BY DESIGN

4
TIRE RATINGS AND DESIGNATIONS

• RATING DETERMINES AMOUNT OF LOAD A TIRE CAN
  HANDLE
• TIRES ARE IDENTIFIED BY PROFILE, ASPECT RATIO,
  SIZE AND LOAD RATING.
• U.S.. AND METRIC SYSTEM TIRE DESIGNATIONS

5
SIDEWALLINFORMATION

• Tire Information is required by law
• Size of tire
• max inflation pressure
• Max Load rating
• generic name of material
• Number of plies on side and tread
• If tubeless or tube type
• Radial designation if applicable
• DOT manufacturing code

6
TIRE SERVICE

• INSPECT TIRES
• ROTATE TIRES
• R R TIRES
• BALANCE TIRES
• REPAIR LEAKS

7
SUSPENSION SYSTEM

• Suspension System supports weight of car
• Most systems have same basic parts
• Frame
• Springs
• Control Arms
• Shock Absorbers
• Tires

8
FRONT SUSPENSION

• Several types of suspensions
• SLA
• MacPherson Strut Front Suspension
• Torsion Bar suspension
• Modified SLA with upper spring
• Suspension system has many parts
• Ball Joints, control arms, springs, Stabilizer
  bars,
• Suspension system must be lubricated regularly

9
REAR SUSPENSION

• Trailing Arm rear suspension
• Rigid Rear suspension
• Independent Rear suspension
• Rear suspension use different type of springs and
  anti-sway bars.

10
SUSPENSION MAINTENANCE

• Lubricate joints
• Chassis Grease
• Inspect for wear
• R R shocks
• Inspect for leakage

11
SHOCK ABSORBERS

• Hydraulic operation
• Gas filled operation
• Located on all four corners of a vehicle
• Shock Absorber Ratio
• Determines rate of compression and extension

12
STEERING SYSTEMS

• Two Main types of steering systems
• Recirculating Ball Type steering gear
• Rack and Pinion steering gear
• Maintenance is limited to checking lube level on
  Recirculatig ball type and visual inspection on
  Rack and Pinion
• Also, must keep Power steering level filled if
  applicable.

13
Steering Linkage

• Contains many parts and so must insure all are
  in good shape.
• Must lubricate linkage when neccesary
• Can cause accidents if excessive play is apparent