Delphi TC4021 Suspension Control Arm and Ball Joint Assembly - Front Left

Front Left Control Arm Assembly

Delphi TC4021 is a front left suspension control arm and ball joint assembly built for OE-style replacement on select Ford, Lincoln applications. It combines a cast iron control arm, pre-greased components, and a threaded ball joint stud to support precise front suspension service on the Ford Flex, Ford Taurus, Lincoln MKS, and Lincoln MKT.

Key Features

• Part number TC4021
• Front left position
• Control arm construction: casting/forged cast iron
• Ball joint included with machined mounting type
• Pre-greased with bushings, dust boot, and mounting hardware included
• Black painted finish with black rubber bushings
• Chloroprene rubber dust boot and boot material
• Non-adjustable design with clockwise (right) thread direction
• Premium grade replacement

OE-Style Fit and Construction

Delphi applies OE-focused dimensional and material analysis to help match the original part’s fit and function. TC4021 is engineered with a cast iron control arm, rubber bushings, a plastic bearing material, and a threaded ball joint stud for front suspension service where accurate geometry matters. Delphi tests parts for temperature extremes below -40 degrees C and above 120 degrees C, along with extended salt-spray exposure, to evaluate durability in demanding conditions. This part cross-references MOOG Chassis Products RK621133 for the same application.

Vehicle Fitment

• Fits 2010-2012 Ford Flex, front left
• Fits 2010-2012 Ford Taurus, front left
• Fits 2009-2012 Lincoln MKS, front left
• Fits 2010-2012 Lincoln MKT, front left

Common Problems This Part Helps Address

• Front-end clunking from a worn control arm or ball joint
• Uneven tire wear caused by suspension looseness
• Steering wander or reduced road feel at the front left corner
• Excess play from deteriorated bushings
• Noisy suspension movement from a damaged dust boot or joint wear

Installation Notes and Tips

Confirm front left placement before installation and compare mounting hole spacing, bushing dimensions, and ball joint orientation to the removed component. Because this assembly is not adjustable, final alignment should be checked after installation. Use the included mounting hardware and locking nut where specified, and verify torque values against the vehicle service information for the Ford Flex, Ford Taurus, Lincoln MKS, or Lincoln MKT.

Quality Assurance

Delphi uses OE-based engineering, dimensional checks, and material analysis to support consistent aftermarket fitment. TC4021 is built and tested to meet demanding environmental conditions, including temperature cycling and salt-spray exposure, to help maintain performance in front suspension service.