U-Joint, 7/8 Smooth To 5/8 36 Spline

OVERVIEW

When you are building a custom sand rail, dune buggy, or a high-performance off-road machine, your steering system is the most critical link between your hands and the terrain. This EMPI Heavy-Duty Universal Joint is engineered to bridge the gap between custom steering columns and standard steering boxes with absolute precision. Designed for the enthusiast who demands more than just a stock setup, this U-joint provides a robust solution for connecting a 7/8-inch smooth steering shaft to a 5/8-inch 36-spline input. Whether you are correcting steering shaft angles due to a lifted suspension or navigating the complexities of a completely custom chassis, this component ensures that every input you make at the wheel is translated into immediate, reliable movement at the tires without the slop associated with worn-out OEM couplers.

Strength and durability are the hallmarks of this EMPI steering component. Manufactured from high-grade steel and designed to withstand the high-torque stresses of off-road racing and rugged trail riding, this U-joint is a significant upgrade over standard rag joints or rubber couplers. The 7/8-inch smooth bore side allows for a versatile "slip-on" fit that can be pinned or welded to your primary steering shaft, while the 5/8-36 spline side is precision-machined to mate perfectly with common manual steering boxes found in the air-cooled VW world. By eliminating the flex of a standard coupler, you gain a much more communicative steering feel, allowing you to sense the limits of traction more effectively. At Appletree Automotive, we know that steering failure is not an option, which is why we recommend this heavy-duty joint for any build where reliability and safety are the top priorities.

FITMENT

• VW Beetle (Standard & Super): Fits manual steering box inputs with 5/8-36 spline.
• VW Karmann Ghia: All years utilizing 5/8-36 spline steering boxes.
• VW Type 3 (Squareback, Fastback, Notchback): All years.
• VW Thing (Type 181): Perfect for off-road steering upgrades.
• Dune Buggies & Sand Rails: Ideal for custom fabrication using 7/8-inch OD steering tubing.
• Baja Bugs: Designed to handle the increased steering angles of long-travel front ends.
• Custom Kit Cars: Any application utilizing a standard VW manual steering box.

SPECS

• Part Number: 17-2787-0
• Brand: EMPI
• Joint Type: Single Universal Joint
• Bore Side A: 7/8-Inch Smooth (Round)
• Bore Side B: 5/8-Inch 36-Spline
• Material: Forged High-Strength Steel
• Finish: Natural Steel (Ready for welding or coating)
• Attachment Style: Set Screw and/or Weld-on
• Application: Steering System Coupler
• Weight: Approximately 0.85 lbs

PRO TIPS

PRO TIP 1: Proper Phasing is Critical. When you are installing multiple U-joints in a single steering system, you must ensure they are "in phase." This means the yokes at either end of the intermediate shaft must be aligned in the same plane. If they are out of phase, you will experience a "lumpy" or binding sensation as you turn the wheel because the joints will be fighting each other''s rotational velocity. Always double-check your alignment before final welding or pinning to ensure the smoothest possible steering operation.

PRO TIP 2: Safety First with Welding. Since one side of this U-joint is a 7/8-inch smooth bore, it is common to weld it directly to your steering shaft. It is imperative that you use a high-quality TIG or MIG weld with deep penetration, as this is a primary safety component. Never cool the weld quickly with water, as this can make the steel brittle. Additionally, wrap the center portion of the U-joint (the needle bearings) with a wet rag during the welding process to prevent heat soak from melting the internal grease or damaging the bearing seals.

PRO TIP 3: Maintenance and Inspection. Unlike a standard rubber rag joint, a mechanical U-joint should be inspected regularly, especially after a weekend in the dunes or on the trail. Check the set screws on the splined end to ensure they haven''t vibrated loose; many builders prefer to use a small amount of blue thread locker and even "dimple" the splined shaft where the set screw seats for extra security. If you ever feel "play" or "clunking" in the steering wheel, inspect the needle bearings in the U-joint cross for wear immediately, as a seized joint can lead to a loss of steering control.