DeLorean Industries "Bullitt Proof" Inconel trailing arm bolt kit. Includes lock nuts and washers. Manufactured by DeLorean Industries from 718 Inconel.

Batch 009 Produced January 2024 Specifications:

• Certified Metallurgical Testing Batch 009
• Ultimate Tensile Strength 211,000 PSI
• Yield Strength (LBS) 26150
• Yield Strength (PSI) 181,250
• ISO/IEC 17025:2017 ACCREDITED, PJLA, ACCREDITATION NO.: 76952, MECHANICAL TESTING.
• TENSILE TEST METHOD: ASTM E8/E8M-21; OTHER: ASTM E29-22. STRAIN RATE: .002 IN./IN./MIN.
• TENSILE TESTS PERFORMED ON MACHINE R-86074 CALIBRATION DUE MAY 2024.

What's in the Box?

• X2 530106883 Inconel Trailing Arm Bolt (TAB)
• X2 530SP10868 22. Washer M12 Stainless
• X2 530SP10178 21. Nut Nyloc M12
• X1 K530106680 Washer Trailing Arm Shim Assortment Stainless

NOTE: There have been reports of Inconel fasteners for this application produced by others not meeting the stringent standards required for the application. Our fasteners are documented through the entire process, engraved with "D-IND 718" for identification, supplied with heat treating certification via our manufacturing partner Paulo and independent metallurgical testing results by third party.

D-Tech Knowledge Base

Trailing Arm Bolts in Application

ABSTRACT

The Delorean rear suspension geometry is triangulated with handed left/right trailing arms, also referred to as “radius” arms. The main arm body ties directly to the rear hub carriers, extending forward to meet at the chassis Rear Y to Mid-box zone. At the front, trailing arm mounting point, a pivoting function is achieved via a complex bushing configuration resulting in a high-stress application on the fastener implemented. The trailing arm bolt (TAB) is responsible for maintaining the rear suspension geometry via a stacked shim configuration and structural integrity of the rear suspension system. Maintaining a high level of application awareness is crucial for this safety-critical suspension component.

FAILURE MODES

Factory fasteners have the notable issue of becoming loose within the assembly and or throw shims. Loosening occurs due to the main fastener nut backing off, inadequate torque, or fastener fatigue. The Fastener is also highly susceptible to corrosion, resulting in the fastener seizing in the trailing arm, and a significantly weakened bolt.

INSPECTION INTERVAL

Trailing arm bolts should be inspected regularly based on driving conditions exhibited. The recommended interval is 500 miles or six months. The check should include confirming the fastener is properly torqued, corrosion issues are not present and shims are in place. It is recommended to document shim placement to assist with the visual check routine.

INSPECTION METHOD

The fasteners are accessed from beneath the car by removing the left and right air deflector plates for the nut side of the fastener, and next to the front of the transmission for the bolt head. Removing the deflectors for the first time will likely require the replacement of the deflector retainer strips.

https://deloreanindustries.com/online-store/frame-body/30-deflector-retaining-strip-stainless-pair/

This is a component pioneered and engineered by DeLorean Industries by implementing a one-piece design with PEM insert studs. Removal for future inspection is simplified by this update.

From inside the chassis, the bolt head is accessible readily on manual transmission cars and with an added amount of effort on automatics. Taking tension of the fastener, rotate the bolt head while observing the trailing arm assembly for movement. If the bolt is damaged or failed, an oscillation movement will occur. If the fastener is unable to rotate, the most likely cause is corrosion in the trailing arm. If rotation cannot be achieved, replacement is required.

If the bolts are the factory's original fasteners, they should be replaced to develop a standard maintenance protocol. If the bolt has been over-torqued, the radius arm bushing sleeve is prone to compression and failure.

SERVICE AND PREVENTATIVE STEPS

While replacing the trailing arm bolts, other components require replacement in most cases. The components below are commonly needed in most cases, with an explanation of the need for implementation.

Automatic cars are inherently more difficult to service due to space constraints. The radius arm bushings are secured to the chassis with two fasteners on a reinforcement bracket. The M8 bolts are secured into nuts built into the chassis. In most applications, a secondary locking jam nut is installed as a secondary security function on the fasteners. Removal is required prior to removing the bushing assembly. Failure to remove the secondary lock nut will result in a shear condition on the M8 fastener. GRP body tub removal is required to correct this condition.

The passenger side rear M8 bolt also doubles as the main chassis ground point for the car. Cleaning this connection point is crucial for the car's electrical system. Inspection of the factory terminal end may show damage or corrosion issues. An upgraded cable assembly is available if required.

Implementation of the proper torque on the trailing arm bolts is crucial to the components functioning properly within the complex system requirements. Failure to properly torque any fastener can result in injury or death. While difficult to achieve, the method of attempting to tighten as best as possible is not acceptable. The trailing arm bolts must be torqued to 55 ft-lb/75 Nm for proper operation.

Updating this fastener to a high-strength, high-corrosion resistance component is the ideal method for the application. DeLorean Industries has engineered and produced a superior Inconel fastener to combat the high-stress and corrosion environment to which this fastener is subject.