Cheat sheet
ASE A4 Cheat Sheet
Steering Systems
- 30% of exam
- Steering Column Steering Gear Power Steering EPS Steering Linkage
Suspension Systems
- 30% of exam
- MacPherson Strut Control Arms Ball Joints Springs Shocks & Struts Stabilizer Bar
Wheel Alignment
- 28% of exam
- Camber Caster Toe SAI Thrust Angle Ride Height
Wheel & Tire Service
- 12% of exam
- Tire Wear TPMS Runout Balance Lug Torque
Quick Facts
- Exam ASE A4
- Credential Suspension & Steering
- Questions 50 (40 scored)
- Time 60 min
- Pass Scaled score 70
- Format Multiple choice, Prometric
- Validity 5 years
- Blueprint 2026 ASE Study Guide
Idler Arm Check Memory Aid ST
- Grasp arm, check vertical then horizontal play
- Vertical: worn socket Horizontal: worn bushing
Hydraulic PS vs EPS ST
Hydraulic
- Belt-driven pump
- Fluid pressure assist
EPS
- Torque sensor plus motor
- Needs relearn or calibration
- Fluid vs electric assist
Noise & Assist Complaint ST
- Moan at full lock → Bleed trapped air ( Cycle lock to lock )
- Directional pressure loss → Suspect gear internal leak
- Column-area clunk → Check U-joint and coupling
- Intermittent EPS assist loss → Check torque sensor and ground
- Excess nose-dive braking → Check shocks/struts ( Not springs )
Steering Column & Linkage ST
- U-joint & flex coupling Column-to-gear connectors
- Collapsible column Crush zone absorbs impact
- Idler arm Check vertical and horizontal play
- Pitman arm Converts gear output motion
- Tie rod ends Check both movement planes
- Center link Connects pitman to linkage
- Airbag column safety Disconnect battery, wait 3 min
EPS Assist Loss Finder ST
- Torque sensor or ground, the two usual suspects
- Sensor: feeds assist calc Ground: voltage integrity
Steering Gear Types ST
- Rack-and-pinion Input shaft seal common leak
- Recirculating ball gear Worm preload plus sector lash
- Worm bearing preload Set before sector lash
- Sector lash Pitman shaft overcenter preload
- Directional pressure test Low one way means gear
- Off-center wheel after gear Recenter wheel, even tie rods
Power Steering (Hydraulic) ST
- PS pump Hydraulic pressure source
- Flow control valve Bypasses excess at high RPM
- Pressure relief valve Caps max system pressure
- PS fluid type ATF or dedicated, per OEM
- Moaning at full lock Air trapped, bleed system
- Flush methods Manual cycle or exchange machine
Electronic Power Steering (EPS) ST
- Torque sensor Feeds assist calculation
- EPS control module Commands motor assist level
- Poor ground fault Causes intermittent assist loss
- Variable assist steering Max low speed, less highway
- EPS relearn After module or rack replace
Ball Joint Load Check SU
- Jack under frame, not the control arm
- Frame: unloads joint Control arm: hides wear
Load-Carrying vs Follower Joint SU
Load-Carrying
- Bears vehicle weight
- Spec: no play allowed
Follower
- No vehicle weight
- Spec: some play OK
- Weight-bearing vs non-load
Front Suspension Components SU
- Control arm bushings Check unloaded with pry bar
- Load-carrying ball joint Bears vehicle weight
- Follower ball joint Non-load, still checked for wear
- SLA ball joint check Jack under frame, not arm
- Excessive nose-dive Points to weak shocks/struts
MacPherson Strut System SU
- Strut mount/bearing Replace with strut, wears out
- Spring compressor Safely transfers coil spring
- Quick strut assembly Pre-assembled spring plus strut
- Strut rod Locates arm fore and aft
Rear Suspension Components SU
- Track bar Controls lateral axle movement
- Watts linkage Alternative lateral axle control
- Leaf spring center bolt Locates spring on axle
- U-bolts Clamp axle, replace when worn
- Shackles and bushings Inspect alongside leaf springs
Springs, Shocks & Stabilizers SU
- Coil spring sag Vehicle leans, replace in pairs
- Ride height check Do before any alignment
- Cupped tire wear Worn shocks/struts, not alignment
- Stabilizer bar bushings Worn means excess body roll
- Bushing torque position Torque at normal ride height
- FWD rear wheel bearing Noise in coast and accel
Alignment Adjustment Order AL
- Caster first, camber second, toe last
- Caster: steering feel Camber: tire wear Toe: final check
Camber vs Caster AL
Camber
- Tilt in/out
- Affects tire wear
- Set 2nd in sequence
Caster
- Fore-aft pivot tilt
- Affects return & effort
- Set 1st in sequence
- Wear vs steering feel
Pull, Wander & Steering Complaint AL
- Pulls one direction → Check cross-caster split ( 0.5 deg matters )
- Wanders at speed → Check toe and tie rods
- Hard steering → Check PS pressure and pump
- Won't self-center → Check caster and binding ( Memory steer )
- Pulls under acceleration → Suspect torque steer ( FWD halfshafts )
- Toe changes over bumps → Suspect bump steer ( Linkage geometry )
Primary Alignment Angles AL
- Camber Inward or outward tire tilt
- Caster Fore-aft pivot, affects return
- Toe Front-rear edge gap, set last
- Thrust angle Rear tracking versus centerline
SAI vs Included Angle AL
SAI
- Fixed, not adjustable
- Built into knuckle
Included Angle
- Camber plus SAI
- Finds bent knuckle
- Fixed vs diagnostic sum
Angle Effects & Diagnosis AL
- Positive camber wear Wears outside tire edge
- Toe-out wear Feathered, inside edges raised
- Cross-caster pull Pulls toward less-positive side
- SAI (KPI) Not adjustable, built into knuckle
- Included angle Camber plus SAI, finds bent knuckle
- Toe-out on turns Checks Ackermann, bent steering arm
Bump Steer vs Torque Steer AL
Bump Steer
- Toe change in travel
- Linkage geometry issue
Torque Steer
- Pulls under acceleration
- Unequal FWD halfshafts
- Suspension vs driveline
Alignment Procedure & Sequence AL
- Ride height first Always check before aligning
- Adjustment order Caster, then camber, then toe
- Memory steer Binding linkage, not misalignment
- Bump steer Toe change through suspension travel
- Torque steer Pulls under power, FWD halfshafts
Tire Wear Cause Finder WH
- Cupped=shocks, feathered=toe, edge=camber, center=air
- Cupped: shocks/struts Feathered: toe One edge: camber Center: overinflation
Static vs Dynamic Imbalance WH
Static
- Single heavy spot
- One weight, either lip
Dynamic
- Heavy spots vary width
- Split weights, both lips
- Single vs split weights
Tire Wear Root Cause WH
- Cupped/scalloped wear → Check shocks and struts
- Feathered wear → Check toe setting
- One-edge wear → Check camber angle
- Center-only wear → Check for overinflation
- Both-edge wear → Check for underinflation
- Vibration, balance OK → Check runout with indicator
Tire Wear Patterns WH
- Feathered wear Toe misadjustment, raised inside edges
- Cupped wear Worn shocks or struts
- One-side camber wear Excess camber on that side
- Center wear Overinflation, tread bulges outward
- Both-edge wear Underinflation, load on shoulders
Direct vs Indirect TPMS WH
Direct
- Sensor per wheel
- Needs relearn after rotation
Indirect
- Uses ABS wheel speed
- No physical sensor
- Sensor vs speed-inferred
TPMS & Tire Service WH
- Direct TPMS In-wheel sensor reads pressure
- TPMS relearn Required after rotation, direct systems
- Slow leak sources Valve stem, bead, or sidewall
- Lug nut pattern Star pattern prevents rotor warp
Runout & Balance WH
- Radial runout Out-of-round, causes ride vibration
- Lateral runout Side-to-side wobble, dial indicator
- Static imbalance Single weight, either rim lip
- Dynamic imbalance Split weights, both rim lips
Common Traps
Ball Joint Play ≠ Automatic Replace
- Some designs have preload ≠ Replace only past spec
Cupped Wear ≠ Alignment Problem
- Cupping is shocks/struts ≠ Feathering is toe
SAI ≠ Adjustable Angle
- SAI is fixed knuckle geometry ≠ Included angle is diagnostic
Bump Steer ≠ Torque Steer
- Bump steer is suspension geometry ≠ Torque steer is driveline
Static Toe ≠ Toe-Out-On-Turns
- Static toe checks straight-line ≠ Turns check Ackermann geometry
Visual Check ≠ Ball Joint Spec
- Visual misses internal wear ≠ Measure load per spec
Pump Noise ≠ Always Pump Fault
- Directional pressure loss is gear ≠ Moan at lock is air
Last Minute
- 1. Steering and suspension: 30% each
- 2. Alignment 28%, wheels/tires 12%
- 3. Order: caster, camber, toe
- 4. Ride height first, always
- 5. Cupped wear means bad shocks
- 6. Feathered wear means toe issue
- 7. SAI is not adjustable
- 8. Jack under frame for SLA
- 9. TPMS relearn after tire rotation
- 10. Lug nuts torque in star pattern
- 11. Disconnect battery before airbag work
ASE A4
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