Woodward Steering Universal Joints – Technical Guide

Woodward Steering Universal Joints – Technical Guide

A technical reference for selecting, identifying and installing Woodward needle-bearing steering U-joints in motorsport steering assemblies. This guide is based on Woodward's Steering Universal Joints, Splined Couplers and Shafts catalog; verify current manufacturer specifications before engineering or installing safety-critical steering components.

Needle-Bearing U-Joint Design

Woodward's motorsport U-joints use preloaded caged needle rollers to minimize backlash and steering friction. The hardened chrome-vanadium trunnion, sealed bearing cups and mechanical bearing-cup retention are designed for precise steering response under demanding racing conditions. Splined joints incorporate set screws for shaft retention.

These are specialist motorsport components, not universal OEM replacement joints. Confirm dimensions and compatibility rather than relying on vehicle make or nominal shaft size alone.

Mechanical Specifications

Property Woodward catalog specification
Approximate joint weight 310 g (varies with bore size)
Rotational clearance circle 1.75 in / 44 mm diameter
Maximum possible angular misalignment 32°
Recommended operating angle Less than 20°
Bearing damage threshold >250 lb-ft / >339 Nm
Plastic deformation threshold >275 lb-ft / >372 Nm
Ultimate breaking torque >300 lb-ft / >406 Nm

These are manufacturer catalog reference values for the joint family, not certified continuous torque ratings. Actual joint mass varies with bore size.

Spline Identification and Connection Codes

Woodward uses three-digit connection codes. Spline diameters are nominal male-shaft dimensions. Count all equally spaced tooth positions, including positions where teeth are missing or blocked; verify the profile and fit before assembly.

Code Nominal size Teeth / profile Typical reference
201 .750 in 20 Woodward proprietary spline; racks, servos, columns and shafts
101 .750 in 48 Sweet and many stock-car racks; some classic British applications
102 .735 in 36 Mustang racks and several older steering gears
103 .720 in 30 GM/Delphi 600 family
104 .820 in 36 Older GM 700-series gears and large Sweet servos
105 .620 in 36 Original Chevrolet Vega steering box
106 .565 in 26 Ford Pinto manual racks
107 .625 in 36 Stiletto (Chassis Shop) racks
108 .688 in / 17.5 mm 34 of 36 Toyota truck spline with blocked position
109 DD; .550 in across flats — Ford-style double-D; not 17 mm GM DD
110 .563 in 36 Titan, Jack Knight and Miller racks
111 .625 in / 16 mm 23 of 36 Australian TRW; some Japanese 16 mm / 36 splines
112 .590 in / 15 mm 29 Honda and some aftermarket racks
113 .570 in / 14.5 mm 28 Datsun 240Z/260Z/280Z
114 .669 in / 17 mm 36 Mitsubishi Starion, Chrysler Conquest, EPAS columns
115 .688 in / 17.5 mm 54 ZF racks on various European vehicles
116 .550 in / 14 mm 34 Toyota MR2, Corolla and Quaife gearsets
100 .755–.753 in Plain bore Close slip fit for 3/4 in OD tubing; weld-on
150 .625 in Plain bore Close slip fit for 5/8 in finished bar; weld-on

Important: spline count and nominal diameter do not guarantee interchangeability. For example, the 105 Vega spline can differ from aftermarket 5/8-36 versions; the 107 spline is a special Stiletto profile. Woodward describes updated 115 joints intended to accommodate old and newer ZF pinion profiles. Check actual fit.

Operating Angle and Steering Smoothness

Woodward specifies a maximum possible single-joint angle of 32°, but recommends an operating angle below 20°. A single U-joint operating at an angle does not transmit perfectly constant rotational velocity: its output accelerates and decelerates twice per revolution. Increasing the angle increases this variation and can affect steering feel.

Where steering geometry requires substantial angular offset, use correctly arranged multiple joints or a supported double universal joint to improve smoothness. Keep angles as small as practical.

Weld-On Joints and Splined Stubs

Woodward connection code 100 is a plain bore intended for 3/4-inch OD tubing, while 150 is intended for 5/8-inch finished bar. These are different fit requirements and must not be treated as splined connections.

The Woodward catalog describes full-circumference fillet welding for weld-on U-joints and specifically warns against plug or rosette welds on the joint body, because bearing distortion and heat damage can result. It also describes weld-in 201 splined stubs as an alternative that keeps welding heat away from the U-joint bearings and allows easier replacement.

Safety: Welding and retention of steering components require qualified fabrication, the manufacturer's full procedure, correct material compatibility and post-installation inspection. This overview is not a welding procedure.

U-Joint Phasing and Clocking

When two U-joints connect sections of a steering shaft, their bearing axes normally need to be phased correctly to minimize speed variation. Incorrect clocking can produce uneven steering response. Woodward's proprietary 201 spline is indexed relative to the bearing axis to facilitate proper phasing on matching Woodward shafts.

Combined angular and parallel offsets may require additional engineering. A double U-joint also requires appropriate shaft support: it is not a rigid, self-supporting coupling.

How to Read Woodward Part Numbers

Woodward U-joint part numbers combine the two three-digit connection codes. For example, UA201115 denotes a 201 Woodward .750-20 spline at one end and a 115 ZF 17.5 mm / 54-tooth spline at the other. UA201150 denotes a 201 spline paired with a 150 plain bore for 5/8-inch bar. Connection selection must follow actual measurements.

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Application and Safety Notice

Woodward identifies these catalog components as intended for motorsport competition. Their suitability for any particular steering installation must be established by the vehicle builder or responsible engineer. Do not assume road-use approval, homologation or compatibility with a particular vehicle. Check the current manufacturer's technical instructions and applicable regulations.

Source: Woodward technical catalog, Steering Universal Joints, Splined Couplers and Shafts, pages 3–14. This Hydroline guide is a condensed, independently written technical overview, not a substitute for the full manufacturer document.

Need help identifying your steering spline?

Contact Hydroline Trade with shaft diameter, tooth count, photographs and the relevant Woodward connection code.

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