Road Safety Leaflet, TP 2436, RS 2000-03E
November 2000
Transport Canada is concerned with reports of leaf spring
failures on commercial vehicles. Inappropriate repairs, lack of vehicle maintenance and
poor inspection practices can result in leaf spring failures.
Operators and technicians are reminded of the importance of
spring care, repairs and installation practices. The following are some important factors
that should be addressed while performing maintenance and/or leaf spring repairs:
- Leaf spring suspensions are often overlooked and neglected.
Inspection of these systems should be part of regular scheduled maintenance and service
programs. During inspection, operators should look for items such as leaf spring
displacement (out of position), cracking or actual breakage of springs and or spring
components, wear or rubbing of spring clips/bands or any other abnormality within the
suspension system. If problems are found, the vehicle should be serviced immediately.
- U-Bolts must be kept tight and must be properly torqued
after a spring has been repaired or replaced. Most manufacturers recommend the use of new
U-bolts and related hardware any time spring repairs are performed. When
installing U-bolts it is important to properly torque the assembly. The suspension should
be retorqued after a short period of operation.
- Adding a leaf to increase the load-carrying capacity should
be reconsidered. All of the suspension parts are designed to carry part of the load.
Adding leaves may result in overloading of other suspension parts or the vehicle itself.
If leaves are added, compatibility should be verified. Do not mix and match different leaf
types. Insure that the system is equipped with all the appropriate parts (i.e. spring
clips/bands). Any modification to the original leaf spring design may seriously damage the
associated parts of the suspension system or the spring itself.
- Spring clips/bands are installed to assist the leaf spring
suspension when exposed to shock and rebound loads and prevents spreading or fanning out
of the leaves. Make certain that broken clips or bands are replaced and are properly
adjusted.
- Never exceed the manufacturers recommended Gross
Vehicle Weight Rating (GVWR) and Gross Axle Weight Rating (GAWR).
Inadequate leaf spring suspension maintenance may result in
serious damage to the vehicle and injury or death to the operator and other users of the
road. Be cautious and take care of your spring and suspension systems.
For additional information regarding this advisory, or to
offer any comments, consult Transport Canada at:
Defect Investigations and Recalls
Road Safety Directorate
Transport Canada
330 Sparks Street,
Tower C, Place de Ville
OTTAWA, Ontario
K1A 0N5
Telephone: 1-800-333-0510 or 1-613-993-9851(Ottawa area)
Fax: 1-613-991-5802
E-mail: RoadSafetyWebMail@tc.gc.ca
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