Delphi TC3991 Suspension Control Arm and Ball Joint Assembly - Front Left Lower

Delphi TC3991 Front Left Lower Control Arm

Delphi TC3991 is a front left lower suspension control arm and ball joint assembly built for the 2018-2021 Honda Accord. It combines an aluminum control arm, pre-greased components, and a bolt-in ball joint for a direct replacement on the front left lower position.

Engineered with Delphi OE-focused dimensional and material analysis, this part is built for accurate fitment on the Honda Accord and consistent steering and suspension performance. The Delphi TC3991 is a practical choice when replacing worn front suspension components on 2018-2021 Honda Accord models.

Key Features

• Fits 2018-2021 Honda Accord, front left lower
• Part number: TC3991
• Aluminum control arm with casting/forged construction
• Ball joint included with threaded stud and bolt-in mounting type
• Pre-greased with bushings, dust boot, and mounting hardware included
• Black rubber bushings and chloroprene rubber dust boot
• Premium grade, uncoated finish, gray control arm color
• Non-adjustable design for direct replacement service

Detailed Description

Delphi TC3991 is a suspension control arm and ball joint assembly for the front left lower position on the 2018-2021 Honda Accord. It uses an aluminum arm with a forged/cast construction, two mounting holes, and a bolt-in ball joint design to match the original suspension layout. The assembly is pre-greased and includes bushings, a dust boot, mounting hardware, and a locking nut for service replacement.

Delphi applies OE-level dimensional and material analysis to help maintain proper alignment geometry and part compatibility. This part cross-references MOOG Chassis Products RK623747 and Mevotech Supreme CMS601270 for the same application. Search terms such as Honda Accord front left lower control arm, 2018-2021 Honda Accord suspension control arm assembly, and Delphi TC3991 front suspension replacement all point to this direct-fit component.

Common Replacement Reasons

• Clunking or knocking from the front suspension
• Excessive play in the lower control arm or ball joint
• Uneven tire wear caused by worn suspension joints
• Steering looseness or wandering on the road
• Cracked bushings or damaged dust boot material

Installation Notes

Install on the front left lower position only. Verify thread direction, mounting hole size, and bushing dimensions against the original part before installation. Because this assembly is non-adjustable, a professional alignment should be performed after replacement on the Honda Accord.

Quality Assurance

Delphi subjects steering and suspension components to extreme temperature testing below -40 degrees C and above 120 degrees C, along with 720 hours of salt spray exposure. These validation steps support OE-style durability for the Delphi TC3991 on 2018-2021 Honda Accord applications.