2021 Ram 3500 Service and Repair Manual

This factory service and repair manual for the 2021 Ram 3500 addresses seven trims: Big Horn, Laramie, Limited, Limited Longhorn, Lone Star, SLT and Tradesman. The body list includes 4-door and 2-door cab and chassis as well as extended crew cab, standard cab and crew cab pickups. Two engines power it, a 6.4L gasoline V8 without forced induction and a 6.7L diesel inline-six with a turbocharger, both using overhead valves. Procedures, specifications, torque values and wiring diagrams are given for the engine, fuel system, transmission, drivetrain, brakes, suspension, steering and electrical system.

Engines covered

• 6.4L V8 (392 cu in) — OHV, naturally aspirated, gasoline
• 6.7L inline-six (408 cu in) — OHV, turbocharged, diesel

Body styles covered

• 4-door cab & chassis
• 4-door extended crew cab pickup
• 2-door standard cab pickup
• 4-door crew cab pickup
• 2-door cab & chassis

Trims covered

• Big Horn
• Laramie
• Limited
• Limited Longhorn
• Lone Star
• SLT
• Tradesman

Known issues on the 2021 3500. The diesel's intake heater is one subject among the nine recalls filed for the 2021 3500. On certain trucks with the diesel engine, the intake heater grid relay could short and start an engine compartment fire even with the ignition off, and owners were told to park outside, clear of buildings, until the repair was done. A faulty steering column control module on certain trucks could prevent the driver air bag from deploying as designed. Certain trucks could also leak transmission fluid from the dipstick tube. There are 62 complaints, led by the electrical system (17), power train (11) and engine (10), and 4 reported a fire. Electrical system wiring diagrams, diagnostics and procedures apply.