Mercedes-Benz Vehicle Models Mercedes C-Class 2014-2021 Torque Specifications
Mercedes-Benz Vehicle Models Mercedes C-Class 2014-2021

Mercedes-Benz Vehicle Models Mercedes C-Class 2014-2021 Torque Specifications

Complete Mercedes-Benz Vehicle Models Mercedes C-Class 2014-2021 torque specifications guide. Includes factory-specified torque values, torque sequences, and technical specifications for all components including body, brakes, drivetrain, electrical, emissions sensors, fuel, exhaust, HVAC, and suspension. Essential information for proper assembly and maintenance.

Updated

Important Information

Safety guidelines and reference information for proper torque application

Quick Reference Guide
ft-lbs → Nm
× 1.356
ft-lbs → kg-m
× 0.138
Nm → ft-lbs
× 0.738
in-lbs → ft-lbs
× 0.083

Common Torque Patterns

Star Pattern

Used for wheels and other circular bolt patterns

Star Pattern torque pattern diagram showing proper bolt tightening sequence
Cross Pattern

Used for gaskets and cover plates

Cross Pattern torque pattern diagram showing proper bolt tightening sequence
Sequential Pattern

Used for head bolts and other critical components

Sequential Pattern torque pattern diagram showing proper bolt tightening sequence

Common Mistakes to Avoid

Over-tightening

Exceeding the specified torque value can stretch or break fasteners, damage threads, or crack components.

Prevention:

Always use a calibrated torque wrench and follow specifications exactly.

Incorrect Torque Sequence

Tightening bolts in the wrong order can cause uneven pressure distribution and potential leaks or damage.

Prevention:

Follow the manufacturer's specified torque sequence pattern.

Dirty Threads

Dirt, rust, or old thread locker can affect torque readings and proper fastener tension.

Prevention:

Clean and inspect all threads before assembly. Use new thread locker if specified.

Reusing TTY Bolts

Torque-to-yield bolts are designed to stretch and must not be reused.

Prevention:

Always replace TTY bolts with new ones. They are single-use only.

Dry vs. Lubricated

Not accounting for whether torque specs are for dry or lubricated fasteners can lead to incorrect tension.

Prevention:

Check if specs are for dry or lubricated threads. Use specified lubricant when required.

Recommended Tools

Torque Wrench (1/4" Drive)

Range: 2-25 ft-lbs
Small fasteners, delicate components

Torque Wrench (3/8" Drive)

Range: 10-100 ft-lbs
Most common automotive fasteners

Torque Wrench (1/2" Drive)

Range: 30-250 ft-lbs
Large fasteners, wheels

Angle Gauge

Torque-to-yield (TTY) bolts

Torque Wrench Care

  • Calibrate annually or after 5,000 clicks
  • Store at lowest setting
  • Keep clean and lubricated

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Search by component name, bolt size, or description

Torque Calculator

Convert between different torque units

1.6l I4 Engine

Torque specifications for 1.6L-I4 Engine

Cylinder Head and Valvetrain

1

Cylinder Head Bolts

M12 x 1.5
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Secure the cylinder head to the engine block.
2

Rocker Arms/Shafts Bolts

M10 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Hold the rocker arms or shafts in place, operating the engine's valve train.
3

Valve Cover Bolts

M8 x 1.25
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Hold the valve cover in place, protecting the engine's valve train and preventing oil leaks.

Engine Block and Crankshaft

1

Main Bearing Bolts

M14 x 1.5
Torque Specification
30 ft-lbs (40 N·m)
Important Notes
Hold the main bearings in place, supporting the crankshaft and maintaining engine stability.
2

Connecting Rod Nuts

M12 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Secure the connecting rods to the crankshaft, allowing for proper piston movement and engine operation.
3

Crankshaft Pulley/Harmonic Balancer Bolt

M16 x 1.5
Torque Specification
81 ft-lbs (110 N·m)
Important Notes
Secure the crankshaft pulley or harmonic balancer, reducing engine vibrations and ensuring proper belt tension.

Timing and Accessory Drive

1

Timing Belt/Chain Tensioner Bolt

M10 x 1.25
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Secure the timing belt or chain tensioner, ensuring proper timing and engine synchronization.
2

Camshaft Sprocket Bolt

M14 x 1.5
Torque Specification
44 ft-lbs (60 N·m)
Important Notes
Attach the camshaft sprocket to the camshaft, driving the engine's valve train.

Engine Mounting and Oil System

1

Engine Mounting Bolts

M14 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Secure the engine to the vehicle's frame, ensuring proper engine alignment and stability.
2

Oil Pan Bolts

M10 x 1.25
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Secure the oil pan to the engine block, containing the engine oil and preventing leaks.
3

Oil Pump Bolts

M12 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Attach the oil pump to the engine, circulating engine oil and lubricating the engine's components.

Intake and Exhaust System

1

Intake Manifold Bolts

M10 x 1.25
Torque Specification
11 ft-lbs (15 N·m)
Important Notes
Attach the intake manifold to the engine, directing airflow and fuel into the cylinders.
2

Exhaust Manifold/Headers Bolts

M12 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Secure the exhaust manifold or headers to the engine, directing exhaust gases away from the engine.

Ignition and Fuel System

1

Spark Plugs

M14 x 1.25
Torque Specification
25 ft-lbs (34 N·m)
Important Notes
Ignite the fuel-air mixture in the engine's cylinders, enabling combustion and engine operation.
2

Fuel Injector Bolts

M8 x 1.25
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Secure the fuel injectors to the intake manifold, delivering fuel to the engine's cylinders.

Cooling System

1

Water Pump Bolts

M10 x 1.25
Torque Specification
6 ft-lbs (8 N·m)
Important Notes
Attach the water pump to the engine, circulating coolant and regulating engine temperature.
2

Thermostat Housing Bolts

M8 x 1.25
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Secure the thermostat housing to the engine, regulating engine temperature and coolant flow.

2.0l I4 Engine

Torque specifications for 2.0L-I4 Engine

Cylinder Head and Valve Train

1

Cylinder Head Bolts

M12 x 1.5
Torque Specification
18 ft-lbs (25 N·m)
2

Valve Cover Bolts

M8 x 1.25
Torque Specification
7 ft-lbs (10 N·m)
3

Rocker Arms/Shafts Bolts

M10 x 1.5
Torque Specification
18 ft-lbs (25 N·m)

Engine Block and Crankshaft

1

Main Bearing Bolts

M14 x 2.0
Torque Specification
30 ft-lbs (40 N·m)
2

Connecting Rod Nuts

M12 x 1.5
Torque Specification
18 ft-lbs (25 N·m)
3

Flywheel Bolts

M16 x 2.0
Torque Specification
58 ft-lbs (80 N·m)

Timing and Accessory Drive

1

Timing Belt/Chain Tensioner Bolt

M10 x 1.5
Torque Specification
15 ft-lbs (20 N·m)
2

Camshaft Sprocket Bolt

M14 x 2.0
Torque Specification
44 ft-lbs (60 N·m)

Engine Mounting and Transmission

1

Engine Block to Transmission Bellhousing Bolts

M14 x 2.0
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Estimated value based on general industry standards.
2

Engine Mounting Bolts

M16 x 2.0
Torque Specification
44 ft-lbs (60 N·m)
Important Notes
Estimated value based on general industry standards.

Intake and Exhaust

1

Intake Manifold Bolts

M10 x 1.5
Torque Specification
11 ft-lbs (15 N·m)
2

Exhaust Manifold/Headers Bolts

M12 x 1.5
Torque Specification
18 ft-lbs (25 N·m)

Cooling and Lubrication

1

Water Pump Bolts

M8 x 1.25
Torque Specification
6 ft-lbs (8 N·m)
2

Oil Pan Bolts

M10 x 1.5
Torque Specification
8 ft-lbs (11 N·m)

Ignition and Fuel

1

Ignition Coil Bolt

M8 x 1.25
Torque Specification
7 ft-lbs (10 N·m)
2

Fuel Injector Bolts

M8 x 1.25
Torque Specification
7 ft-lbs (10 N·m)

3.0l Engine

Torque specifications for 3.0L Engine

Cylinder Head

1

Cylinder Head Bolts

M10 x 1.5
Torque Specification
1. 18 ft-lbs (25 N·m) 2. 90°
Important Notes
Tighten in the specified sequence to ensure even clamping force.
2

Valve Cover Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure the valve cover gasket is properly seated before tightening.

Crankshaft Assembly

1

Main Bearing Bolts

M10 x 1.5
Torque Specification
30 ft-lbs (40 N·m)
Important Notes
Ensure bearings are properly seated before tightening.
2

Flywheel Bolts

M12 x 1.75
Torque Specification
58 ft-lbs (80 N·m)
Important Notes
Use thread locker on bolt threads for added security.

Piston Assembly

1

Connecting Rod Nuts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure rod bearings are properly seated before tightening.

Cooling System

1

Water Pump Bolts

M6 x 1.0
Torque Specification
6 ft-lbs (8 N·m)
Important Notes
Ensure the gasket is properly seated before tightening.
2

Thermostat Housing Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure the gasket is properly seated before tightening.

Intake And Exhaust

1

Intake Manifold Bolts

M8 x 1.25
Torque Specification
11 ft-lbs (15 N·m)
Important Notes
Ensure the gasket is properly seated before tightening.
2

Exhaust Manifold Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure the gasket is properly seated before tightening.

3.0l V6 Engine

Torque specifications for 3.0L-V6 Engine

Cylinder Head

1

Cylinder Head Bolts

M10 x 1.5
Torque Specification
1. 18 ft-lbs (25 N·m) 2. 90°
Important Notes
Tighten in the specified sequence to ensure even clamping force.
2

Valve Cover Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure the valve cover gasket is properly seated before tightening.

Crankshaft Assembly

1

Main Bearing Bolts

M10 x 1.5
Torque Specification
30 ft-lbs (40 N·m)
Important Notes
Ensure bearings are properly seated before tightening.
2

Flywheel Bolts

M12 x 1.75
Torque Specification
58 ft-lbs (80 N·m)
Important Notes
Use thread locker on bolt threads for added security.

Piston Assembly

1

Connecting Rod Nuts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure rod bearings are properly seated before tightening.

Cooling System

1

Water Pump Bolts

M6 x 1.0
Torque Specification
6 ft-lbs (8 N·m)
Important Notes
Ensure the gasket is properly seated before tightening.
2

Thermostat Housing Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure the gasket is properly seated before tightening.

Intake And Exhaust

1

Intake Manifold Bolts

M8 x 1.25
Torque Specification
11 ft-lbs (15 N·m)
Important Notes
Ensure the gasket is properly seated before tightening.
2

Exhaust Manifold Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure the gasket is properly seated before tightening.

7g Tronic Transmission

Torque specifications for 7g Tronic Transmission

Transmission Mounting

1

Transmission Mounting Bolts

M12 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Proper torque ensures proper alignment and minimizes vibration.

Transmission Oil Pan

1

Transmission Oil Pan Bolts

M8 x 1.25
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Proper torque ensures a leak-free seal and maintains transmission fluid pressure.

Transmission Fluid System

1

Transmission Drain and Fill Plugs

M14 x 1.5
Torque Specification
29 ft-lbs (40 N·m)
Important Notes
Proper torque ensures a secure seal to prevent leaks and maintains fluid pressure.
2

Transmission Fluid Drain/Fill Plug

M14 x 1.5
Torque Specification
29 ft-lbs (40 N·m)
Important Notes
Proper torque ensures a secure seal to prevent leaks and maintains fluid pressure.

Transmission Case

1

7G-Tronic Transmission case bolts

M12 x 1.5
Torque Specification
30 ft-lbs (40 N·m)
Important Notes
Estimated value. Proper torque ensures a secure seal and maintains the transmission's structural integrity.

Torque Converter

1

Torque converter bolts

M14 x 1.5
Torque Specification
44 ft-lbs (60 N·m)
Important Notes
Estimated value. Proper torque ensures a secure connection and maintains the transmission's performance.

Output Shaft

1

Output shaft nut

M20 x 1.5
Torque Specification
80 ft-lbs (110 N·m)
Important Notes
Estimated value. Proper torque ensures a secure connection and maintains the transmission's performance.

Input Shaft Bearing Cap

1

Input shaft bearing cap bolts

M10 x 1.25
Torque Specification
25 ft-lbs (34 N·m)
Important Notes
Estimated value. Proper torque ensures a secure seal and maintains the transmission's performance.

9g Tronic Transmission

Torque specifications for 9g Tronic Transmission

Transmission Mounting

1

Transmission Mounting Bolts

M12 x 1.5
Torque Specification
37 ft-lbs (50 N·m)

Transmission Oil Pan

1

Transmission Oil Pan Bolts

M10 x 1.5
Torque Specification
8 ft-lbs (11 N·m)

Transmission Fluid System

1

Transmission Fluid Drain and Fill Plugs

M14 x 1.5
Torque Specification
29 ft-lbs (40 N·m)
2

Transmission Fluid Drain/Fill Plug

M14 x 1.5
Torque Specification
29 ft-lbs (40 N·m)

Transmission Pan

1

9G-Tronic Transmission Pan Bolts

M10 x 1.5
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Estimated value based on industry standards.

Transmission Filter

1

9G-Tronic Transmission Filter Bolts

M8 x 1.25
Torque Specification
10 ft-lbs (14 N·m)
Important Notes
Estimated value based on industry standards.

Transmission Cooler Lines

1

9G-Tronic Transmission Cooler Line Fittings

M12 x 1.5
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Estimated value based on industry standards.

Transmission Solenoid Pack

1

9G-Tronic Transmission Solenoid Pack Bolts

M6 x 1
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Estimated value based on industry standards.

Body

Torque specifications for Body

Suspension System

1

Strut/Shock Absorber Mounting Bolts

M14 x 1.5
Torque Specification
89 ft-lbs (120 N·m)
2

Control Arm Bolts

M14 x 1.5
Torque Specification
89 ft-lbs (120 N·m)
3

Ball Joint Nut

M16 x 1.5
Torque Specification
48 ft-lbs (65 N·m)
4

Sway Bar Link Nut

M12 x 1.25
Torque Specification
37 ft-lbs (50 N·m)

Steering System

1

Steering Gear/Rack Bolts

M14 x 1.5
Torque Specification
80 ft-lbs (110 N·m)
2

Tie Rod End Nut

M12 x 1.25
Torque Specification
44 ft-lbs (60 N·m)

Body and Frame

1

Body Mounting Bolts

M16 x 1.5
Torque Specification
50 ft-lbs (70 N·m)
Important Notes
Estimated value. Consult repair manual for exact specification.
2

Door Hinge Bolts

M10 x 1.25
Torque Specification
20 ft-lbs (30 N·m)
Important Notes
Estimated value. Consult repair manual for exact specification.
3

Hood and Trunk Lid Hinge Bolts

M8 x 1.25
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Estimated value. Consult repair manual for exact specification.
4

Bumper Mounting Bolts

M12 x 1.25
Torque Specification
30 ft-lbs (40 N·m)
Important Notes
Estimated value. Consult repair manual for exact specification.

Brakes

Torque specifications for Brakes

Brake Caliper System

1

Brake Caliper Bolts

M12 x 1.5
Torque Specification
81 ft-lbs (110 N·m)
Important Notes
Ensure proper alignment of the caliper during installation.
2

Brake Caliper Mounting Bracket Bolts

M12 x 1.5
Torque Specification
81 ft-lbs (110 N·m)
Important Notes
Ensure the bracket is properly aligned with the steering knuckle or axle.

Brake Rotor Drum System

1

Brake Disc/Drum Retaining Bolts

M12 x 1.5
Torque Specification
81 ft-lbs (110 N·m)
Important Notes
Ensure the rotor or drum is seated properly on the hub.

Brake Hydraulic System

1

Brake Hose Banjo Bolt

M10 x 1.0
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure the sealing washers are properly installed to prevent leaks.
2

Brake Master Cylinder Mounting Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure the master cylinder is properly aligned with the brake booster.
3

Brake Booster Mounting Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure the booster is properly aligned with the firewall.

Brake Pedal System

1

Brake Pedal Pivot Bolt

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure the pedal moves freely after installation.

Abs System

1

ABS Sensor Mounting Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure the sensor is properly aligned with the tone ring.

Wheel System

1

Wheel Lug Nuts

M12 x 1.5
Torque Specification
96 ft-lbs (130 N·m)
Important Notes
Always torque lug nuts in a star pattern to ensure even clamping force.

Drivetrain

Torque specifications for Drivetrain

Engine Block and Crankshaft

1

Flywheel Bolts

M12 x 1.5
Torque Specification
58 ft-lbs (80 N·m)
Important Notes
Proper torque is essential to prevent damage to the flywheel, crankshaft, and transmission.
2

Main Bearing Bolts

M10 x 1.25
Torque Specification
30 ft-lbs (40 N·m)
Important Notes
Proper torque ensures the bearings are securely fastened and prevents engine damage.

Connecting Rods and Pistons

1

Connecting Rod Nuts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Proper torque is crucial to prevent engine damage and ensure proper engine operation.

Crankshaft Pulley and Harmonic Balancer

1

Crankshaft Pulley/Harmonic Balancer Bolt

M14 x 1.5
Torque Specification
81 ft-lbs (110 N·m)
Important Notes
Proper torque is essential to prevent damage to the pulley/balancer and crankshaft.

Transmission and Bellhousing

1

Transmission Mounting Bolts

M12 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Proper torque ensures the transmission is properly aligned and supported.
2

Engine Block to Transmission Bellhousing Bolts

M10 x 1.25
Torque Specification
30 ft-lbs (40 N·m)
Important Notes
Proper torque ensures proper alignment and prevents damage to the engine and transmission.

Transmission Oil Pan and Crossmember

1

Transmission Oil Pan Bolts

M8 x 1.25
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Proper torque prevents oil leaks and ensures proper transmission operation.
2

Transmission Crossmember Bolts

M12 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Proper torque ensures proper transmission alignment and prevents damage to the transmission and chassis.

Drive Axle and Half Shaft

1

Drive Axle/Half Shaft Bolts

M14 x 1.5
Torque Specification
59 ft-lbs (80 N·m)
Important Notes
Proper torque ensures proper axle alignment and prevents damage to the axles and transmission.

CV Joint and Axle Nut

1

CV Joint/Axle Nut

M18 x 1.5
Torque Specification
181 ft-lbs (245 N·m)
Important Notes
Proper torque ensures proper CV joint operation and prevents damage to the axle and CV joint.

Propeller and Drive Shaft

1

Propeller/Drive Shaft Bolts

M14 x 1.5
Torque Specification
66 ft-lbs (90 N·m)
Important Notes
Proper torque ensures proper drive shaft alignment and prevents damage to the drive shaft and transmission.

Differential and Cover

1

Differential Drain/Fill Plug

M12 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Proper torque prevents fluid leaks and ensures proper differential operation.
2

Differential Cover Bolts

M10 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Proper torque prevents fluid leaks and ensures proper differential operation.

Driveshaft Center Bearing

1

Driveshaft Center Bearing Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Proper torque ensures proper driveshaft alignment and prevents damage to the driveshaft and center bearing.

Electrical

Torque specifications for Electrical

Alternator and Starter System

1

Alternator Mounting Bolts

M10 x 1.5
Torque Specification
18 ft-lbs (25 N·m)
2

Starter Motor Mounting Bolts

M12 x 1.75
Torque Specification
30 ft-lbs (40 N·m)

Battery and Electrical Connectors

1

Battery Terminal Nuts

M8 x 1.25
Torque Specification
5 ft-lbs (7 N·m)
Important Notes
Be careful not to over-torque, as this can damage the terminals.
2

Fuel Pump Electrical Connector Bolts

M6 x 1.0
Torque Specification
1. 5 ft-lbs (7 N·m) 2. 7 ft-lbs (10 N·m)
Important Notes
Estimated torque values based on general industry guidelines. Consult the vehicle's repair manual or manufacturer's documentation for specific torque values.
3

Power Steering Pump Electrical Connector Bolts

M6 x 1.0
Torque Specification
1. 5 ft-lbs (7 N·m) 2. 7 ft-lbs (10 N·m)
Important Notes
Estimated torque values based on general industry guidelines. Consult the vehicle's repair manual or manufacturer's documentation for specific torque values.

Ignition System

1

Ignition Coil Mounting Bolts

M10 x 1.5
Torque Specification
1. 10 ft-lbs (14 N·m) 2. 12 ft-lbs (16 N·m)
Important Notes
Estimated torque values based on general industry guidelines. Consult the vehicle's repair manual or manufacturer's documentation for specific torque values.

Emissions Sensors

Torque specifications for Emissions_sensors

EGR System

1

EGR Valve Bolts

M10 x 1.5
Torque Specification
6 ft-lbs (8 N·m)
Important Notes
Proper torque ensures a secure connection and prevents leaks.

Exhaust Manifold And Headers

1

Exhaust Manifold/Headers Bolts

M12 x 1.75
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Proper torque ensures a secure connection and prevents leaks.
2

Exhaust Manifold/Headers to Cylinder Head Bolts

M12 x 1.75
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Proper torque ensures a secure connection and prevents leaks.

Catalytic Converter

1

Catalytic Converter to Exhaust Pipe Bolts

M10 x 1.5
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Proper torque ensures a secure connection and prevents leaks.

Oxygen And NOx Sensors

1

Oxygen Sensor Bolts

M8 x 1.25
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Estimated value based on industry standards. Proper torque ensures a secure connection and prevents damage to the sensor.
2

NOx Sensor Bolts

M8 x 1.25
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Estimated value based on industry standards. Proper torque ensures a secure connection and prevents damage to the sensor.

Exhaust

Torque specifications for Exhaust

Exhaust Manifold Headers

1

Exhaust Manifold/Headers to Cylinder Head Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure bolts are tightened in a crisscross pattern to evenly distribute pressure.
2

Exhaust Pipe to Exhaust Manifold/Headers Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure a secure connection to prevent leaks.

Catalytic Converter

1

Catalytic Converter to Exhaust Pipe Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure a secure connection to prevent leaks.

Muffler

1

Muffler to Exhaust Pipe Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure a secure connection to prevent leaks.

Heat Shield

1

Exhaust Heat Shield Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Estimated value based on typical heat shield bolt sizes.

Oxygen Sensor

1

Oxygen Sensor (O2 Sensor) Mounting Bolts

M10 x 1.25
Torque Specification
30 ft-lbs (40 N·m)
Important Notes
Ensure a secure connection to prevent leaks and ensure accurate sensor readings.

Exhaust Hanger

1

Exhaust Hanger Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure a secure connection to prevent excessive movement of the exhaust system.

Exhaust Flange

1

Exhaust Flange Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure a secure connection to prevent leaks.

Fuel

Torque specifications for Fuel

Fuel Rail System

1

Fuel Rail Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure bolts are tightened in a crisscross pattern to evenly distribute pressure.
2

Fuel Injector Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure injectors are properly seated before tightening.

Fuel Pump And Tank System

1

Fuel Pump Mounting Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure the fuel pump is properly aligned before tightening.
2

Fuel Tank Strap Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure the fuel tank is properly supported before tightening.
3

Fuel Tank Sender Unit Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure the sender unit gasket is properly seated to prevent leaks.

Fuel Delivery System

1

Fuel Filler Neck Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure the filler neck is properly aligned with the fuel tank.
2

Fuel Filter Bolt/Nut

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure the fuel filter is properly seated before tightening.
3

High-Pressure Fuel Line Fittings

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure fittings are properly aligned and seated before tightening.
4

Fuel Line Clamp Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure clamps are properly positioned to secure fuel lines.

Fuel Pressure Regulation

1

Fuel Pressure Regulator Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure the regulator is properly seated before tightening.

Hvac

Torque specifications for Hvac

Air Conditioning System

1

A/C Compressor Mounting Bolts

M10 x 1.5
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Proper torque ensures the compressor is securely fastened to the engine block or bracket.
2

A/C Line Fittings

M10 x 1.5
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Proper torque ensures a leak-free seal, preventing refrigerant loss and maintaining system pressure.
3

A/C Condenser Mounting Bolts

M12 x 1.75
Torque Specification
17.5 ft-lbs (23.7 N·m)
Important Notes
Estimated value. Proper torque ensures the condenser is securely fastened to the radiator support or bracket.
4

A/C Evaporator Mounting Bolts

M8 x 1.25
Torque Specification
12.5 ft-lbs (16.9 N·m)
Important Notes
Estimated value. Proper torque ensures the evaporator is securely fastened to the dashboard or HVAC module.
5

A/C Refrigerant Line Bracket Bolts

M8 x 1.25
Torque Specification
12.5 ft-lbs (16.9 N·m)
Important Notes
Estimated value. Proper torque ensures the lines are securely fastened to the engine compartment or chassis.
6

A/C Compressor Clutch Bolt

M14 x 2.0
Torque Specification
22.5 ft-lbs (30.5 N·m)
Important Notes
Estimated value. Proper torque ensures the clutch is securely fastened to the compressor.

Suspension

Torque specifications for Suspension

Strut and Shock Absorber Mounting

1

Strut/Shock Absorber Mounting Bolts

M14 x 1.5
Torque Specification
89 ft-lbs (120 N·m)
Important Notes
Proper torque is crucial to prevent damage to the strut/shock absorber and maintain ride quality.

Control Arm and Steering Components

1

Control Arm Bolts

M12 x 1.25
Torque Specification
89 ft-lbs (120 N·m)
Important Notes
Proper torque ensures the control arms are securely attached, maintaining proper suspension geometry and preventing damage to surrounding components.
2

Ball Joint Nut

M16 x 1.5
Torque Specification
48 ft-lbs (65 N·m)
Important Notes
Proper torque is essential to prevent the ball joint from coming loose, which can cause uneven tire wear and affect vehicle stability.
3

Tie Rod End Nut

M14 x 1.25
Torque Specification
44 ft-lbs (60 N·m)
Important Notes
Proper torque ensures the tie rod end is securely attached, maintaining proper steering alignment and preventing damage to surrounding components.
4

Sway Bar Link Nut

M12 x 1.25
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Proper torque ensures the sway bar link is securely attached, maintaining proper suspension stability and preventing damage to surrounding components.

Upper and Lower Control Arm Bushings

1

Upper Control Arm Bushing Bolts

M10 x 1.25
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Estimated value. Proper torque is essential to prevent the bushings from coming loose, which can cause uneven tire wear and affect vehicle stability.
2

Lower Control Arm Bushing Bolts

M10 x 1.25
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Estimated value. Proper torque is essential to prevent the bushings from coming loose, which can cause uneven tire wear and affect vehicle stability.

Steering Knuckle and Hub Bearing

1

Steering Knuckle Bolts

M14 x 1.5
Torque Specification
75 ft-lbs (102 N·m)
Important Notes
Estimated value. Proper torque is essential to prevent the steering knuckle from coming loose, which can cause uneven tire wear and affect vehicle stability.
2

Hub Bearing Bolts

M14 x 1.5
Torque Specification
75 ft-lbs (102 N·m)
Important Notes
Estimated value. Proper torque is essential to prevent the hub bearing from coming loose, which can cause uneven tire wear and affect vehicle stability.

Troubleshooting Guide

Common issues, diagnostic steps, and prevention guidelines

Common Issues

Bolt stretching, stripped threads, uneven torque patterns

Loose Components

Symptoms:
  • Rattling or vibration noises
  • Visible movement in components
  • Uneven panel gaps
Solutions:
  • Clean threads and mounting surfaces
  • Replace damaged fasteners
  • Apply proper torque in sequence
  • Use thread locker if specified

Stripped Fasteners

Symptoms:
  • Unable to achieve proper torque
  • Fastener spins freely
  • Visible thread damage
Solutions:
  • Use thread repair kit if appropriate
  • Install thread insert (HeliCoil)
  • Replace component if threaded hole is damaged
  • Upgrade to higher grade fastener if recommended

Overtightened Components

Symptoms:
  • Cracked or deformed parts
  • Broken fasteners
  • Compressed gaskets or seals
Solutions:
  • Replace damaged components
  • Use new fasteners
  • Follow proper torque sequence
  • Verify correct torque specifications

Diagnostic Steps

Visual inspection, torque verification, thread assessment

1

Visual Inspection

Inspect the affected area for any visible signs of damage or wear

  • Check for cracks or deformation
  • Look for signs of excessive wear
  • Verify proper fastener installation
2

Torque Verification

Verify the torque applied to the fasteners

  • Check the torque wrench calibration
  • Verify the torque specification
  • Compare the applied torque to the specification
3

Thread Assessment

Assess the condition of the threads

  • Check for signs of thread damage
  • Verify the thread type and size
  • Check for proper thread engagement

Prevention Guidelines

Best practices, maintenance tips, tool care

Best Practices

  • Always follow the recommended torque specification
  • Use the correct type and size of fasteners
  • Verify the torque wrench calibration regularly

Maintenance Tips

  • Regularly inspect the affected area for signs of wear or damage
  • Replace damaged or worn-out components promptly
  • Keep the work area clean and organized

Tool Care

  • Regularly clean and maintain the torque wrench
  • Store the torque wrench in a dry and secure location
  • Verify the torque wrench calibration before each use

Frequently Asked Questions

Find answers to common questions about torque specifications

Q1

What are the recommended torque specifications for lug nuts on my 2014-2021 Mercedes c-class?

Hand-tighten the lug nuts, then use a torque wrench to further tighten them to 120 ft-lbs.

Q2

What IS the correct torque for spark plugs on my 2014-2021 Mercedes c-class?

Tighten the spark plugs to 25 ft-lbs.

Q3

What tools do I need to properly torque bolts on my 2014-2021 Mercedes c-class?

You will need a torque wrench with a range that covers the specified torque values for your vehicle.

Q4

How do I ensure accurate torque measurements on my 2014-2021 Mercedes c-class?

Always verify the torque wrench accuracy before using it. To ensure accuracy, calibrate the wrench according to manufacturer instructions.

Q5

What are the risks of over-torquing or under-torquing bolts on my 2014-2021 Mercedes c-class?

Over-torquing can damage the threads or strip the bolt. Under-torquing may result in the bolt loosening, leading to potential component failure.

Q6

Where can I find additional torque specifications for my 2014-2021 Mercedes c-class?

Refer to the Mercedes service manual or consult a qualified mechanic for vehicle-specific torque specifications and guidelines.

Environmental Considerations

Temperature, humidity, and seasonal effects on torque specifications

Temperature Effects

Includes: High Heat, Cold Weather, Thermal Cycling

Temperature can significantly impact torque values and fastener behavior

Cold Weather

Effects:
  • Increased material brittleness
  • Higher torque required due to thread contraction
  • Reduced thread lubricant effectiveness
Recommendations:
  • Allow components to warm to room temperature when possible
  • Consider using winter-grade thread lubricants
  • Check torque values more frequently during winter months

Hot Weather

Effects:
  • Thermal expansion of components
  • Decreased friction in threads
  • Accelerated lubricant breakdown
Recommendations:
  • Check torque when components are at normal operating temperature
  • Use temperature-resistant thread lockers
  • Consider re-torquing after heat cycles

Humidity and Corrosion

Covers: Rust Prevention, Salt Exposure, Moisture Control

Moisture and corrosion can affect fastener integrity and torque values

High Humidity

Effects:
  • Accelerated corrosion formation
  • Reduced friction coefficient
  • Potential thread seizing
Prevention:
  • Use corrosion-resistant fasteners
  • Apply appropriate anti-seize compounds
  • Maintain proper protective coatings

Salt Exposure

Effects:
  • Rapid corrosion development
  • Thread damage
  • Seized fasteners
Prevention:
  • Regular underbody washing
  • Use of sacrificial anodes where appropriate
  • Application of protective coatings

Seasonal Maintenance

Spring, Summer, Fall, and Winter maintenance schedules

Spring

  • Inspect for winter damage
  • Clean and protect exposed fasteners
  • Check torque on critical components

Summer

  • Monitor heat-affected components
  • Check expansion-related loosening
  • Inspect cooling system mounts

Fall

  • Prepare for winter conditions
  • Apply corrosion protection
  • Verify all fasteners are properly torqued

Winter

  • More frequent inspection of critical fasteners
  • Check for salt damage
  • Monitor suspension component torque

Related Resources

Tools, service procedures, and technical bulletins

Recommended Tools

Digital Torque Wrench (10-100 Nm)

Essential for tightening fasteners to precise torque specifications, preventing damage and ensuring proper assembly. This range IS suitable for many applications on the c-class.

  • Digital display for accurate readings
  • Audible alarm when target torque IS reached
  • Multiple units (Nm, ft-lb, in-lb)
  • Reversible ratcheting mechanism
Learn more
Service Procedures

Bolt Torque Specifications for the 2014-2021 Mercedes C-Class

Provides detailed technical guidance on tightening bolts to the correct torque values for various components on the C-Class.

  • Safety precautions and general instructions
  • Torque values for engine components, suspension, brakes, and more
  • Special considerations for specific bolts and fasteners
  • Maintenance schedule recommendations
View full procedure
Technical Service Bulletins

Technical Service Bulletin: Incorrect Bolt Torque Specifications for 2018-2020 C-Class Models

2020-06-15

Addresses an issue where incorrect bolt torque specifications were provided in the service manual for certain 2018-2020 C-Class models. Provides updated torque values and instructions.

2018-2020 Mercedes-Benz C-Class

Resolution: Refer to the updated service manual or technical bulletin for the correct torque specifications. Ensure that all bolts are tightened accordingly to prevent potential safety concerns.

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Technical Information
  • All specifications, including torque values, fluid capacities, and maintenance procedures, should be verified against your vehicle's factory service manual.
  • Vehicle specifications and procedures may vary by model year, trim level, and region.
  • Always follow the manufacturer's recommended procedures and safety precautions.
  • Working on vehicles can be dangerous. Always take proper safety precautions and use appropriate safety equipment.
  • If you're unsure about any procedure, consult a qualified professional mechanic.
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About the Author

Expert automotive knowledge and experience

Alan Montanye - Automotive Technical Specialist
ASE

Alan Montanye

Automotive Technical Specialist

ASE Master Certified Technician with over a decade of hands-on experience in automotive repair and diagnostics.

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