FAQs

Thordon manufactures 4 grades of propeller shaft bearings for different operating environments – COMPAC for blue water operation, XL and SXL for varying degrees of abrasives and RiverTough for the most abrasive water conditions.  They are proprietary synthetic elastomeric polymer alloys combining the best properties of plastic with the toughness and abrasion resistance of rubber. See the Thordon Bearing Grade & Configuration Selection Chart.

0.15 litres/minute/mm (1 U.S.Gallon/minute/inch) of shaft diameter.  Thordon also requires less water flow than rubber.

The best liner to use in dirty water environment is a Nickel Chrome Boron coated liner with a surface hardness greater than 50 Rockwell C.

The maximum operating pressure is 0.6 MPa (87 psi), which is limited by Classification Societies.

Not recommended, as the temperature from engine cooler can be hotter than allowable for the bearing.

The RiverTough bearing has a higher level of abrasion resistance than competing rubber tail shaft bearings.  The RiverTough bearing only requires a 3/1 LD ratio where competing rubber tail shaft bearings require a 4/1 LD ratio.

No, the RiverTough bearing does not wear out the liner/sleeve.  The wear on the liner/sleeve comes from the sandy/silty slurry that is swirling around the shaft during operation.  This has been a misconception for years that has arisen from the rubber tail shaft bearing being replaced at the same time as the liner/sleeve while the liner/sleeve is often replaced at the second or third liner/sleeve replacement.

For the best wear life, it is recommended that the mating surface to RiverTough be a surface that is at least 40 Rockwell C.