The drum brake is known for its sturdiness in use on commercial vehicles. This is mainly because of the bearings that have to function well over the long term and withstand dirt, salt water, and many other adverse effects. Re-greasing of the bearings is often not possible and in many cases not even desirable. Therefore bushings and bearings have to be adjusted accordingly.
Bushings made of solid materials like Wieland S31 and Wieland B09 have long demonstrated their capability to fulfil the necessary requirements. Both materials are outstanding with regard to their resistance to wear and to salt water.
Perforated bushings are highly recommended as they are able to absorb a large quantity of grease. The bushings are available as standard in accordance with DIN ISO 3547 (formerly DIN 1494) and can be delivered quickly from stock. If the use of standard bushings is not possible, they can be adjusted to the prevailing conditions and specially manufactured.