Cv Joint, Off-Road Prep, 108mm for 930 Porsche 28 Spline

Elevate Your Off-Road Performance with the EMPI 930 Off-Road Prep CV Joint

When you are pushing the limits of a long-travel suspension system in a high-performance sand rail, Baja Bug, or custom off-road buggy, the standard street-grade components simply will not cut it. This EMPI Off-Road Prep 108mm CV Joint is specifically engineered to handle the brutal articulation and high-torque demands of the 930 Porsche-style drivetrain. Unlike a standard replacement joint, this unit features a specialized "Off-Road Prep" which means the tolerances between the balls and the tracks are intentionally clearanced. This loose-fit design is critical for off-roaders because it allows the joint to achieve its maximum operating angle without binding or overheating, ensuring that your power is delivered smoothly even when your suspension is at full droop or compression.

Durability is the cornerstone of this assembly, featuring a high-strength Chromoly cage that is significantly tougher than the stock cast versions found in lower-tier kits. The solid outer race and the 28-spline inner race are precision-machined to withstand the shock loads common in desert racing and dune jumping. By utilizing 0.875-inch balls, the surface area for load distribution is optimized, reducing the risk of cage failure or ball-stripping. Whether you are building a weekend warrior or a dedicated race machine, upgrading to these EMPI 108mm joints provides the peace of mind that your driveline won''t be the weak link when you are miles away from the trailer. It''s the industry standard for a reason: it combines Porsche-level engineering with the ruggedness required for the most demanding terrain on the planet.

Vehicle Fitment and Compatibility

This 108mm 930-style CV joint is a universal high-performance component typically used in custom air-cooled VW and off-road applications. Please verify your axle spline count and flange size before ordering.

• VW Beetle / Baja Bug: Fits custom long-travel rear suspension setups utilizing 930-style drive flanges.
• Sand Rails & Dune Buggies: The primary choice for mid-engine and rear-engine rails using 28-spline performance axles.
• Porsche 911 / 930 Turbo: Replacement for 1975-1989 models requiring the 108mm flange (verify spline count).
• VW Type 2 Bus / Transporter: Used in extreme off-road conversions where 002 or 091 transaxles have been upgraded to 930 flanges.
• Custom Off-Road Vehicles: Compatible with any 28-spline high-performance axle designed for 108mm CV joints.

Technical Specifications and Materials

• Outside Diameter: 108mm (Approximately 4.25 inches).
• Spline Count: 28-Spline Inner Race.
• Ball Diameter: 0.875 inches.
• Cage Construction: High-Strength Chromoly Steel.
• Race Design: Solid Outer Race for maximum structural integrity.
• Internal Preparation: Custom "Off-Road Prep" (Loose fit for high-angle articulation).
• Finish: Precision machined and heat-treated components.
• Manufacturer Part Number: 87-9470-B.

Professional Installation Tips from the Appletree Specialist

Tip 1: Proper Lubrication and "Burping" the Boot

Never skimp on the grease when installing these high-angle joints. We recommend using a high-quality, high-moly content grease specifically designed for CV joints. When packing the joint, ensure the grease is worked deep into the cage and around every ball. Once the boot is installed and clamped, it is a pro-level move to "burp" the boot. Simply insert a small, blunt screwdriver between the boot and the axle to let out excess air. This prevents the boot from ballooning or collapsing due to pressure changes and heat, which is a leading cause of premature boot failure during high-speed desert runs.

Tip 2: Understanding Clocking and Grooves

Pay close attention to the orientation of the inner race and the cage during assembly if you ever take the joint apart for cleaning. The inner race has a wide side and a narrow side between the ball tracks; these must be "clocked" correctly with the outer race to allow for movement. If you assemble it incorrectly, the joint will lock up and won''t provide the travel you need. Additionally, look for the machined grooves on the faces of the races. These are often used as reference points to ensure the joint is assembled exactly as it was balanced and clearanced at the factory.

Tip 3: Routine Maintenance and Rotation

In the off-road world, CV joints are a wear item, but you can double their lifespan with proper maintenance. After every few trips, we recommend removing the joints, cleaning out the old grease, and inspecting the tracks for "pitting" or "galling." If you see minor wear starting on one side of the track, you can rotate the joint (swap the driver''s side to the passenger''s side) to change the load point on the tracks. This allows the balls to ride on a fresh surface, effectively giving you a "second life" out of a set of joints before they require full replacement.