Section 2 - Suspension
- Suspension and Frame Attachments
- Axle Attaching and Tracking Components
- Axle and Axle Assembly
- Spring and Spring Attachment
- Air Suspension
- Self-Steer and Controlled-Steer Axle
- Shock Absorber/Strut Assembly
- MORryde Suspension
- Multi-Link/Independent Rear Suspension
- Computer Controlled Air Suspension System
All inspection procedures are visual unless additional inspection procedures are indicated or where applied force is necessary to verify tightness and/or component security. The definitions can be found in the “Definitions and Acronyms” section.
1. Suspension and Frame Attachments
Additional Inspection Procedure(s): Raise the vehicle as necessary to access the suspension components.
Note: This section applies to all types of suspension. welding of components is a normal part of many manufacturing processes and is distinct from welding to modify or repair a part.
Item and method of inspection | Reject if | Inspection Class |
|---|---|---|
a) vehicle ride height Additional Inspection Procedure(s): | a) on vehicles with a of less than 4500 kg: suspension is sagged so that the vehicle ride height is more than 38 mm from specified height track bar or any other suspension component extends down below the lowest part of the wheel rim one side of the vehicle is more than 38 mm, higher or lower than the other when measured at the tire centerline the vehicle's suspension can be independently controlled from inside the vehicle (unless the controller is designed and installed by the original vehicle at the time of manufacture) on vehicles with a of 4500 kg or more: suspension is sagged so that the vehicle ride height, on a vehicle other than a , is more than 50 mm from specified height when measured at the tire centerline one side of the vehicle is more than 50 mm, higher or lower than the other when measured at the tire centerline on a , step height at an entrance door is 25 mm above or below the range of step height specified by the | 1, 2, 3, 4, 5, 6 |
b) suspension lift / raised vehicle Additional Inspection Procedure(s): Height measurements must be recorded for headlights, front bumper, tire size and overall vehicle height. | b) vehicle modification or components not designed for use on highway | 1, 2, 3, 4, 5, 6 |
c) lift block Note: Applies to leaf suspension. | c) if installed on front axle (other than ) | 1, 2, 4, 5 |
d) frame bracket, mounting bracket and hanger Note: Some trailer suspension systems use a “cross tube brace”, consisting of a pipe positioned between the spring hangers on either side of the vehicle. The “cross tube brace” is used to position the suspension for shipment and installation and has no bearing on the alignment or the function of the suspension. | d) broken, cracked, , , , or perforated due to corrosion or deterioration welded or repaired in a way that does not meet standard , , broken, cracked, worn in excess of 3 mm (1/8 in.) at the hanger bolt hole | 1, 2, 3, 4, 5, 6 |
e) mounting fasteners | e) broken, cracked, or | 1, 2, 3, 4, 5, 6 |
f) mounting tower | f) misaligned or modified, corrosion holes present, any area corroded to such a depth as to show evidence of metal fatigue, section repairs other than metal and sections welded in other than by an approved method, attaching bolts are , , inferior type, bent and/or misaligned rusted through so that the strut could come detached | 1, 2, 4, 5, 6 |
g) upper strut bearing | g) , binding, worn, shifted from its normal position | 1, 2, 4, 5 |
i. an axle has shifted or is able to shift from its normal position
ii. any attaching component is broken, cracked, or
iii. the condition of the suspension system allows a tire to contact any part of the vehicle frame or body
2. Axle Attaching and Tracking Components
Additional Inspection Procedure(s): Raise the vehicle as per procedures to access the suspension components. Inspect using hand pressure and suitable tools.
Note: This section applies to all types of suspension.
Item and method of inspection | Reject if | Inspection Class |
|---|---|---|
a) axle attachment, axle saddle | a) bent, broken, cracked, or axle has shifted from its normal position | 1, 2, 3, 4, 5, 6 |
b) bushing (rubber or composite material) | b) or shifted out of place, , worn beyond specification wear or damage permits axle or wheel to shift out of position | 1, 2, 3, 4, 5, 6 |
c) suspension connecting component, (e.g.: arm, torque rod, radius rod, strut, track rod, control arm) Note: Some suspension connecting components are supplied as unfinished two-piece assemblies that require welding once the required length is | c) bent, broken, cracked, , , worn beyond specifications, or perforated due to corrosion or deterioration welded or repaired in a way that does not meet standard wear or damage permits axle or wheel to shift out of position | 1, 2, 3, 4, 5, 6 |
d) stabilizer/anti-sway bar or link | d) bent, broken, cracked, , , welded, disconnected or worn beyond specification | 1, 2, 3, 4, 5, 6 |
e) equalizer or “walking” beam | e) broken, cracked or bushing mounting holes are elongated welded or repaired in a way that does not meet standard wear in suspension allows tires to contact frame axles do not align correctly on a truck or truck-tractor, “walking” beam cross tube bushing has more than 7 mm clearance | 2, 3, 4, 5 |
i. an axle has shifted or is able to shift from its normal position
ii. any attaching or tracking component is broken, cracked, or
iii. the condition of the suspension system allows a tire to contact any part of the vehicle frame or body
3. Axle and Axle Assembly
Item and method of inspection | Reject if | Inspection Class |
|---|---|---|
a) condition | a) axle is bent, , or shifted out of normal position axle material or weld is cracked repaired by welding in a way that does not meet standard | 1, 2, 3, 4, 5, 6 |
i. axle has shifted or is able to shift from its normal position
ii. axle material or a weld is cracked
4. Spring and Spring Attachment
Item and method of inspection | Reject if | Inspection Class |
|---|---|---|
a) leaf spring | a) any spring leaf is broken, cracked, , , or is shifted out of place any spring leaf is worn more than 3 mm in the hanger contact area or where leaves are in contact with each other shifted so as to be less than 13 mm (1/2 in.) from any rotating part, or contacting another vehicle part | 1, 2, 3, 4, 5, 6 |
b) composite spring Note: Some change in the appearance of a composite spring, described as “” is normal as the spring ages. A crack of a composite spring is a separation in any axis which passes completely through the spring. | b) , broken, crack of any length visible on both sides of a spring splintered, separating, delaminating or not the same type on each side of vehicle on inspection class 2, 3, 4 and 5 vehicles: worn more than 3 mm in load bearing area | 1, 2, 3, 4, 5, 6 |
c) coil spring | c) , , broken or shifted out of normal position spacer is used between the coils of a spring Note: Spacers allowed under or on top of coil spring. welded, repaired or modified in a way that does not meet the standard | 1, 2, 3, 4, 5, 6 |
d) torsion bar | d) broken, cracked, or welded, repaired or modified in a way that does not meet the standard | 1, 2, 3, 4, 5 |
e) shackle, pin, bushing Additional Inspection Procedure(s): | shifted out of normal position fastener or vertical movement of a spring or shackle against a spring pin exceeds standard or if not available; wear exceeds limit below
shackles extended in a manner that does not meet the Standard | 1, 2, 3, 4, 5, 6 |
f) U-bolt & hardware | f) broken, cracked, , , or shifted out of normal position welded or repaired in a way that does not meet standard | 1, 2, 3, 4, 5, 6 |
g) spring contact area of hanger (slipper) Note: Wear plates are permitted by some manufacturers in the spring contact (slipper) area of fabricated hangers. | g) repaired by welding (except installation of wear plates) spring load bearing area is worn more than 3 mm | 1, 2, 3, 4, 5, 6 |
h) bump pad | h) , , split or | 1, 2, 3, 4, 5 |
i) rubber load cushion | i) rubber block or vertical pin is broken, , or split | 2, 3, 4, 5 |
j) centre bolts | j) , welded, broken, , misaligned | 1, 2, 3, 4, 5, 6 |
i. any metal spring leaf is , or has leaves shifted out of place
ii. the main leaf or more than 25% of the leaves of a metal leaf spring are cracked
iii. spring leaf is shifted and in contact with a rotating part
iv. any spring is broken
v. a composite spring has a crack of any length intersecting with another crack, or a crack longer than ¾ the length of the spring
vi. torsion bar is broken or cracked
vii. a rubber load cushion is or separated
5. Air Suspension
Note: This section applies to fixed axle and liftable axle suspension systems.
Additional Inspection Procedure(s):
Check with air system at normal operating pressure, liftable suspension in lowered position, and with supports placed under the vehicle to protect against dropping of the vehicle in the event of air loss. Maintain appropriate air pressure in any liftable axle system.
Item and method of inspection | Reject if | Inspection Class |
|---|---|---|
a) ride height | a) height is 50 mm above or below specification vehicle leans to one side or air spring pressure is unequal | 1, 2, 3, 4, 5 |
b) air spring (air bag) | b) improperly seated, , patched or reinforcing ply is exposed due to damage or deterioration air leak | 1, 2, 3, 4, 5 |
c) air spring base, mounting plate | c) broken, cracked or perforated by corrosion or deterioration welded or repaired in a way that does not meet standard | 1, 2, 3, 4, 5 |
d) air system Additional Inspection Procedure(s): | d) pressure protection valve is or control, pressure regulator or gauge, is or | 1, 2, 3, 4, 5 |
e) airline, connection and fitting Note: Refer to correct type of hose or tube and the related defective condition(s) as defined in Appendix B. | e) fitting, line, repair method, installation or modification does not meet standard tubing or hose is defective as defined in Appendix B fitting or connection is broken, cracked, flattened or leaking in a way (such as: melting, flattening, deformation or kinking) that can restrict air flow | 1, 2, 3, 4, 5 |
f) height control valve | f) a system originally equipped with 2 valves has a valve or has been converted to a single valve a system with only one valve has the valve positioned in a location other than near the center of an axle | 1, 2, 3, 4, 5 |
g) kneeling feature on a Additional Inspection Procedure(s): | g) audible or visual warning is | 4, 5 |
h) pressure protection valve | h) air goes to suspension before brake system tank pressure reaches 450 kPa (65 psi) | 2, 3, 4, 5 |
i. an air spring (air bag) is , deflated or has an air leak
6. Self-Steer and Controlled-Steer Axle
Note: The suspension components on a self-steer or controlled steer axle must be inspected according to items 1 - 4 in this Section. The steering components must be inspected according to Section 4 of this Vehicle Inspection Manual.
7. Shock Absorber/Strut Assembly
Item and method of inspection | Reject if | Inspection Class |
|---|---|---|
a) condition | a) , detached, or binding strut bearing/mount prevents free rotation of the steering wheel | 1, 2, 3, 4, 5, 6 |
b) mount & hardware | b) broken, or | 1, 2, 3, 4, 5, 6 |
c) oil leak | c) of oil | 1, 2, 3, 4, 5, 6 |
d) bushings | d) , deteriorated, rubber excessively dispersed | 1, 2, 3, 4, 5, 6 |
e) positioning | e) shock not located at each position | 1, 2, 3, 4, 5, 6 |
f) type (hydraulic cylinder) | f) hydraulic cylinder not certified for on-highway use | 1, 2, 3, 4, 5, 6 |
i. a shock absorber on coil, spring or air ride suspension is broken, detached, or
8. MORryde Suspension
Note: All bolts shall be torqued to specifications.
Item and method of inspection | Reject if | Inspection Class |
|---|---|---|
a) attachment to frame | a) bolts , | 1, 2, 3, 4, 5 |
b) attachment to axle | b) cracked, broken, , | 1, 2, 3, 4, 5 |
c) clearance between frame and U-bolts | c) any component does not clear frame | 1, 2, 3, 4, 5 |
d) U-bolts | d) , not torqued to specification | 1, 2, 3, 4, 5 |
e) rubber banding (check with 3 in. measuring device) | e) separation of rubber in excess of 19 mm (3/4 in.) in depth from steel plate | 1, 2, 3, 4, 5 |
f) crossmember at suspension | f) , broken, cracked, | 1, 2, 3, 4, 5 |
i. any component allows the axle to shift from its normal position.
ii. any attaching component is , , cracked or broken.
9. Multi-Link/Independent Rear Suspension
Item and method of inspection | Reject if | Inspection Class |
|---|---|---|
a) spring | a) , welded, improperly seated in spring saddle, sagged so as to lower the vehicle more than 38 mm (1 1/2 in.) from specified height | 1, 2, 4, 5, 6 |
b) ball joints | b) exceed tolerances, in knuckle or control arm | 1, 2, 4, 5, 6 |
c) stabilizer bar/links | c) , bent, broken, , disconnected, welded, , bushing brackets and bolts or | 1, 2, 4, 5, 6 |
d) suspension members | d) , bent, disconnected, broken, , welded, | 1, 2, 4, 5, 6 |
e) control arm | e) bent, , cracked, welded, bushings | 1, 2, 4, 5, 6 |
f) knuckles | f) bent, welded, distorted | 1, 2, 4, 5, 6 |
g) pivot bolts | g) , bent, welded, nuts or , threads stripped | 1, 2, 4, 5, 6 |
h) anchor bolts | h) , bent, welded, nuts or , threads stripped | 1, 2, 4, 5, 6 |
i) rear axle carrier (if equipped) | i) any attaching or tracking component is , bent, disconnected, , welded or | 1, 2, 4, 5, 6 |
i. any spring is broken
ii. any attaching or tracking component is , , cracked and or/broken
10. Computer Controlled Air Suspension System
Additional Inspection Procedure(s): Control switch must be in “OFF” position if vehicle is being hoisted or raised.
Item and method of inspection | Reject if | Inspection Class |
|---|---|---|
a) air springs | a) , cut, , , leaking, patched, spring rubber cracked to first braid, vehicle leans to one side, any air spring is deflate | 1, 2, 3, 4, 5, 6 |
b) lines | b) , crushed, cracked, disabled, leaking, restricted, insecurely mounted | 1, 2, 3, 4, 5, 6 |
c) spring mounting | c) brackets or bolts or , bolt threads stripped, spring in mount | 1, 2, 3, 4, 5, 6 |
d) compressor | d) , insecurely mounted, | 1, 2, 3, 4, 5, 6 |
e) compressor relay (if equipped) | e) , | 1, 2, 3, 4, 5, 6 |
f) control module | f) , | 1, 2, 3, 4, 5, 6 |
g) height sensors | g) , , , improperly located | 1, 2, 3, 4, 5, 6 |
h) switch | h) , , disconnected | 1, 2, 3, 4, 5, 6 |
i) warning lamp | i) during test cycle | 1, 2, 3, 4, 5, 6 |
i. any air spring is deflated