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 manufacturer’s 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