Axle Bearing Housing Spacer, For Removing Backing Plate

OVERVIEW

When you are upgrading your air-cooled Volkswagen to a high-performance disc brake system or building a rugged off-road machine with boxed trailing arms, you will inevitably run into a spacing issue at the rear axle. The original drum brake backing plate serves a dual purpose: it holds the brake shoes, but it also acts as a critical 3/16-inch spacer between the bearing housing and the trailing arm or axle flange. If you simply remove the backing plate and bolt the housing back on, you lose that necessary thickness, which prevents the bearing housing from seating properly. This leads to a lack of compression on the vital O-rings and gaskets, resulting in persistent gear oil leaks and potential movement of the axle bearing itself. This Latest Rage Axle Bearing Housing Spacer is the professional solution to this problem, providing the exact offset required to maintain the structural integrity of your rear suspension without the need for cumbersome, modified factory parts.

Engineered for precision and durability, this spacer is a staple for any serious VW builder working on IRS (Independent Rear Suspension) or Swing Axle configurations. It is specifically designed for applications where you are using weld-on brake brackets or custom caliper mounts that do not incorporate the original backing plate thickness. By utilizing this spacer, you ensure that the bearing housing puts the correct amount of "clamp" on the outer bearing race. This is especially important for Baja Bugs, sand rails, and street cars where reliability is paramount. Instead of "hacking up" a perfectly good set of vintage backing plates just to salvage the center ring, this clean, laser-cut steel spacer provides a professional finish and a perfect fit every single time. It is the "missing link" in your rear disc brake conversion that keeps your gear oil in the transaxle and your bearings locked firmly in place.

FITMENT

This axle bearing housing spacer is designed for a wide range of air-cooled Volkswagen models equipped with standard 4-bolt bearing housings. Fitment includes:

• Volkswagen Beetle (Type 1): 1950 through 1979 (All Swing Axle and IRS models).
• Volkswagen Karmann Ghia: 1956 through 1974.
• Volkswagen Type 3 (Squareback, Fastback, Notchback): 1962 through 1973.
• Volkswagen Thing (Type 181): 1973 through 1974.
• Custom Applications: Ideal for Dune Buggies, Sand Rails, Woods Buggies, and Baja Bugs using stock-style trailing arms or boxed aftermarket arms.

SPECS

Detailed technical specifications for the AC501490S spacer:

• Part Number: AC501490S
• Material: Heavy-duty cold-rolled steel for maximum compression resistance.
• Thickness: 3/16 inches (0.1875"), matching the factory backing plate flange.
• Inner Diameter (ID): 3.04 inches to clear the bearing housing shoulder.
• Bolt Pattern: 2 1/2 inches x 2 1/2 inches (Standard VW 4-bolt rear housing).
• Overall Length: 3.938 inches.
• Overall Width: 3.716 inches.
• Finish: Raw steel (ready for paint, powder coat, or installation as-is).
• Compatibility: Works with both IRS and Swing Axle rear ends.

PRO TIPS

1. Don''t Forget the Gasket Sandwich

Even though you are using this spacer to replace the backing plate, you must still maintain the proper sealing sequence. The standard setup should involve a paper gasket between the trailing arm and the spacer, and another paper gasket between the spacer and the bearing housing. This, combined with the large and small O-rings inside the housing, ensures a leak-free seal. Always use a small amount of high-quality gasket sealant or a wipe of gear oil on the paper gaskets to help them seat perfectly during the torquing process.

2. Verify Your Bolt Length

When you remove the thick factory backing plate and install this 3/16-inch spacer, you are maintaining the original geometry. However, many aftermarket disc brake brackets or heavy-duty bearing housings have different flange thicknesses. After installing the spacer, ensure that your four housing bolts have at least 1/2-inch of thread engagement into the trailing arm or axle flange. Conversely, make sure the bolts are not so long that they bottom out before the housing is fully tight. Proper torque on these bolts is essential to prevent the housing from "walking" under heavy acceleration or off-road vibration.

3. Check for Burrs and Flatness

Before installation, always inspect the mounting surface of your trailing arm and the bearing housing for old gasket material or nicks in the metal. Because this spacer is a precision-cut flat piece of steel, any debris trapped behind it will prevent a liquid-tight seal. We recommend using a flat file to lightly "dress" the mounting surfaces of your trailing arms to ensure they are perfectly flat. If you are using boxed trailing arms, ensure the weld beads don''t interfere with the spacer sitting flush against the bearing carrier area.