Mounting and dismounting

Y-bearings and Y-bearing units are reliable machine elements that can provide long service life, provided they are mounted and maintained properly. Proper mounting requires experience, accuracy, a clean work environment and the appropriate methods and tools.

Failure to carefully follow applicable mounting instructions can result in premature bearing failure or improper performance. For detailed information, contact the SKF application engineering service.

The method used for mounting a Y-bearing unit depends on:
  • the overall machine design
  • the Y-bearing housing design
  • the method by which the unit is locked onto the shaft
Leave the Y-bearings, housings for Y-bearings or Y-bearing units in their original packages until immediately prior to mounting so that they are not exposed to any contaminants.
Before mounting a Y-bearing unit, check that the shaft and machine rails are clean and free of any burrs. Also be sure that the shaft seat is within tolerance (table 1) and the machine rails have appropriate dimensions to fit into the housing piloting groove.


To mount or dismount Y-bearing units, the following tools are required:
  • a hexagonal key or torque key to tighten the grub (set) screws in the inner ring or the eccentric locking collar as specified in the product tables
  • a hook spanner with a stud to tighten or loosen the eccentric locking collar
  • a hook spanner to tighten adapter sleeve lock nuts as specified in the product table

Grub screws / adapter sleeve lock nuts should be tightened to the torque values / tightening angles listed in the product tables. The tightening angles, listed for bearings on an adapter sleeve, are to be used as guideline values only, as it is difficult to establish an exact starting position.

Hook spanners are part of the comprehensive SKF assortment of high quality mounting and maintenance products. For information about SKF maintenance products, refer to Maintenance products.

For additional information about mounting and dismounting Y-bearings and assembling Y-bearing units, refer to the SKF bearing maintenance handbook.
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