Timken397-90163Tapered Roller Bearing TDO Assembly – 2.3622 in Bore, 4.3307 in Cup OD, 2.0624 in Width Across Cones, Two Rows, Double Cup and Cone Spacer, Case-Hardened Steel

Product Description

What this part is

Timken 397-90163 tapered roller bearing assembly in the TDO (tapered double outer) configuration. The -90163 suffix marks a complete factory assembly: two 397 cones, one 394D double cup and one X1S-397 cone spacer. Bore is 2.3622 in (60 mm), cup outside diameter 4.3307 in (110 mm), and overall width across the cones 2.0624 in (52.385 mm).

Quantity and configuration

One complete assembly. It contains two cones, the double cup and the spacer that sets the internal geometry between the two rows.

Decoding the designation

A Timken -90xxx suffix denotes a complete assembly rather than a loose cone or cup. The D on 394D marks a double cup, one outer ring carrying two opposed raceways. The X1S prefix on X1S-397 marks a cone spacer, which fixes the axial distance between the two cones and therefore the mounted internal setting of the pair.

Ratings and factors

Two-row dynamic radial rating is 38,700 lbf (172,000 N) at 1 million revolutions and 10,000 lbf (44,600 N) at 90 million revolutions. The single-row figures within the assembly are 5,760 lbf (25,600 N) radial and 3,970 lbf (17,600 N) thrust at 90 million revolutions. The K factor is 1.45, the e factor 0.40, Y1 is 1.68, Y2 is 2.50 and the geometry factor Cg is 0.0984.

What these specs mean in practice

A TDO puts the two effective load centres outboard of the bearing itself, which gives a wide effective bearing spread in a short axial envelope. That is what makes the configuration the standard answer where overturning moments are a significant part of the load — wheel ends, pinion mountings, spindles carrying an overhung pulley or gear. Because the spacer sets the internal geometry at the factory, the assembly arrives with its setting fixed rather than requiring adjustment at the shaft. The double cup can be clamped in a fixed position or left to float in the housing bore, so the same assembly serves as either a locating or a non-locating position.

Fitting notes

Cone backface backing diameter is 2.72 in (69 mm) and the cup frontface backing diameter is 4.12 in (104.65 mm). Maximum fillet radii cleared by the bearing corners are 0.03 in at the cone backface and 0.030 in at the cup backface. Cage-cone backface clearance is 0.05 in and the effective centre location is -0.03 in, inside the cone backface. Cage material is stamped steel and the rings are case-hardened steel.

Interchange guidance

Timken builds the same 397 cone and 394D double cup into several other assembly numbers — 397-90077, 397-90078, 397-90079, 397-90082, 397-90083, 397-90269, 397-902A3 and 397-90331. Those share the 2.3622 in bore and 4.3307 in outside diameter but differ in spacer width and internal setting, so they are related assemblies on a common envelope rather than direct substitutions. The loose 397 cone and 394D double cup sold separately cover the same geometry without the factory setting.