1. Selecting the pressing cylinder:
To press-fit silent blocks with a polyurethane outer surface (fig. 5), force can be applied to the polyurethane layer from the face of the part by placing the projecting portion of the inner sleeve into the pressing cylinder opening. The diameter of the opening must be 1 – 2 mm greater than the diameter of the sleeve to avoid nicking it. The edge of the opening and the outer edge of the pressing cylinder must have chamfers or must be blunt, again to prevent nicking the polymer layer. The lower part of the installation hole must allow the silent block’s inner sleeve to enter unimpeded.
The inner sleeve sometimes extends slightly beyond the outer surface (by up to 2 – 3 mm). In that case, the pressing cylinder may not have a central hole (fig. 6); all other requirements must the observed. The press can apply force to the internal sleeve directly.
2. The press-fit process:
The mounting seat’s surface must be sufficiently coated with lubricant before installation. Once at least half of the silent block has entered the hole, it is recommended to briefly release the pressing force in order to allow the silent block’s polyurethane layer to freely fill the grooves on the surface that were specially made for that purpose during manufacture of the part.
Application of the pressing force must cease when the upper edge of the polyurethane layer (top, bead) is reached in order to prevent nicking the edge of the opening in the arm or rod. The press-fit silent block must protrude beyond the mounting seat evenly (as a rule).
If that is not achieved on the first try, the seating force can be applied again as needed to straighten the part in the control arm (rod).