IRS Trailing Arm Pivot Bolt (only)

VW IRS Trailing Arm Pivot Bolt & Washers – 113-501-535A

The IRS Trailing Arm Pivot Bolt is a specialized high-tensile hardware piece used to secure the diagonal arm (trailing arm) to the inner pivot bracket. On many air-cooled Volkswagens, the original factory bolt is a 17mm Allen-head style that is notorious for coming loose or being difficult to remove after decades of road use.

This replacement is often upgraded to a hex-head design for easier installation and service. Because it serves as the main pivot point for the rear suspension, it is a critical safety item that must withstand constant vibration and torque.

Detailed Vehicle Compatibility

This bolt is used on all models equipped with Independent Rear Suspension (IRS) across the following years:

VW Beetle & Super Beetle

• 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979

VW Karmann Ghia

• 1968, 1969, 1970, 1971, 1972, 1973, 1974

VW Type 3 (Notchback, Squareback, Fastback)

• 1968, 1969, 1970, 1971, 1972, 1973

VW Thing (Type 181)

• 1973, 1974

Product Highlights & Features

• Improved Design: Features a standard hex-head for better tool grip compared to the original internal Allen-head, which often strips out.

• Complete Hardware: Typically includes the specialized thick washers required to prevent the bolt from backing out and to protect the bracket surface.

• High-Strength Grade: Manufactured to high-tensile specifications to handle the heavy side-loading and pivoting forces of the rear suspension.

• Corrosion Resistant: Zinc-plated to protect the threads and head from moisture and road salt.

Technical Specifications

• Part Number: 113501535A

• Application: Rear IRS Diagonal Arm Pivot

• Components: 1 Bolt 

• Quantity Required: 2 per vehicle (one for each side)

Installation & Maintenance Tips

• Safety First: The stock pivot bolt is notorious for coming loose over time. Some builders prefer to use pre-drilled bolts for safety wire to ensure they stay locked in place under racing or heavy off-road conditions.

• Torque Sequence: Always torque this bolt to 60–65 ft-lb only once the vehicle is on the ground at its normal ride height. Torquing it while the suspension is hanging can bind the bushings.

• Avoid "Slop": If you are reinstalling trailing arms, this is the best time to check your IRS Arm Bushings. If the hole in the bushing sleeve is ovaled or the rubber is cracked, the new bolt won't be able to hold a proper alignment.

**Note: 1968 Years will fit for Semi-Auto or Fully Auto Transmissions**