Mercedes-Benz Mercedes CLS 2018-present Drivetrain Bolt Torque Specifications
Detailed torque specifications for the drivetrain bolts of the 2018-Present Mercedes-Benz CLS, including engine, transmission, and differential fasteners.
Important Information
Safety guidelines and reference information for proper torque application
Safety First
- Always verify torque specifications with your vehicle's factory service manual
- Use properly calibrated torque wrenches
- Replace all torque-to-yield (TTY) bolts - they are single-use only
- When in doubt, consult a professional mechanic
Quick Reference Guide
Quick Reference Guide
Common Torque Patterns
Star Pattern
Used for wheels and other circular bolt patterns
Cross Pattern
Used for gaskets and cover plates
Sequential Pattern
Used for head bolts and other critical components
Common Mistakes to Avoid
Common Mistakes to Avoid
Over-tightening
Exceeding the specified torque value can stretch or break fasteners, damage threads, or crack components.
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.
Follow the manufacturer's specified torque sequence pattern.
Dirty Threads
Dirt, rust, or old thread locker can affect torque readings and proper fastener tension.
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.
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.
Check if specs are for dry or lubricated threads. Use specified lubricant when required.
Recommended Tools
Recommended Tools
Torque Wrench (1/4" Drive)
Torque Wrench (3/8" Drive)
Torque Wrench (1/2" Drive)
Angle Gauge
Torque Wrench Care
- Calibrate annually or after 5,000 clicks
- Store at lowest setting
- Keep clean and lubricated
Search Specifications
Search by component name, bolt size, or description
Torque Calculator
Convert between different torque units
Engine To Transmission
Components that secure the engine to the transmission, ensuring proper alignment and preventing damage.
1 Flywheel Bolts
M12 x 1.5
Flywheel Bolts
M12 x 1.5Torque Value
2 Engine Block to Transmission Bellhousing Bolts
M14 x 1.5
Engine Block to Transmission Bellhousing Bolts
M14 x 1.5Torque Value
Important Notes
Transmission Mounting
Components that secure the transmission to the engine block or transmission crossmember.
1 Transmission Mounting Bolts
M12 x 1.5
Transmission Mounting Bolts
M12 x 1.5Torque Value
2 Transmission Crossmember Bolts
M14 x 1.5
Transmission Crossmember Bolts
M14 x 1.5Torque Value
Important Notes
Transmission Oil Pan
Components that secure the transmission oil pan to the transmission case.
1 Transmission Oil Pan Bolts
M10 x 1.5
Transmission Oil Pan Bolts
M10 x 1.5Torque Value
Transmission Drain And Fill
Components that allow for transmission fluid changes and maintenance.
1 Transmission Drain and Fill Plugs
M12 x 1.5
Transmission Drain and Fill Plugs
M12 x 1.5Torque Value
Drive Axle Half Shaft
Components that secure the drive axles or half shafts to the transmission or differential.
1 Drive Axle/Half Shaft Bolts
M14 x 1.5
Drive Axle/Half Shaft Bolts
M14 x 1.5Torque Value
2 Drive Axle/Half Shaft Nut (at the wheel hub)
M16 x 1.5
Drive Axle/Half Shaft Nut (at the wheel hub)
M16 x 1.5Torque Value
Important Notes
Cv Joint Axle
Components that secure the CV joint to the axle shaft.
1 CV Joint/Axle Nut
M16 x 1.5
CV Joint/Axle Nut
M16 x 1.5Torque Value
Propeller Drive Shaft
Components that secure the propeller shaft or drive shaft to the transmission or differential.
1 Propeller/Drive Shaft Bolts
M12 x 1.5
Propeller/Drive Shaft Bolts
M12 x 1.5Torque Value
Differential Drain Fill
Components that allow for differential fluid changes and maintenance.
1 Differential Drain/Fill Plug
M12 x 1.5
Differential Drain/Fill Plug
M12 x 1.5Torque Value
Transfer Case Drain Fill
Components that allow for transfer case fluid changes and maintenance.
1 Transfer Case Drain/Fill Plug
M12 x 1.5
Transfer Case Drain/Fill Plug
M12 x 1.5Torque Value
Differential Cover
Components that secure the differential cover to the differential case.
1 Differential Cover Bolts
M10 x 1.5
Differential Cover Bolts
M10 x 1.5Torque Value
Important Notes
Transfer Case Mounting
Components that secure the transfer case to the transmission or vehicle frame.
1 Transfer Case Mounting Bolts
M12 x 1.5
Transfer Case Mounting Bolts
M12 x 1.5Torque Value
Important Notes
Troubleshooting Guide
Common issues, diagnostic steps, and prevention guidelines
Common Issues
Bolt stretching, stripped threads, uneven torque patterns
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
Diagnostic Steps
Visual inspection, torque verification, thread assessment
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
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
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
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 is the torque specification for the drivetrain bolts on a 2018-Present Mercedes CLS?
What is the torque specification for the drivetrain bolts on a 2018-Present Mercedes CLS?
The torque specifications for drivetrain bolts vary depending on the specific component. For example, the driveshaft-to-differential bolts typically require 70-80 Nm (52-59 lb-ft), while transmission mounting bolts may require 40-50 Nm (30-37 lb-ft). Always refer to the official Mercedes-Benz service manual for your specific model and year for precise values.
Q2 How often should I check the torque on drivetrain bolts?
How often should I check the torque on drivetrain bolts?
It is recommended to check the torque on drivetrain bolts during routine maintenance, such as every 30,000 miles or after any significant drivetrain work. Loose bolts can lead to vibrations, noise, or even component failure, so regular inspection is crucial.
Q3 Can I reuse drivetrain bolts after removal?
Can I reuse drivetrain bolts after removal?
Reusing drivetrain bolts is generally not recommended, as they are often designed as single-use torque-to-yield bolts. Reusing them can compromise their integrity and lead to failure. Always replace with new, manufacturer-approved bolts.
Q4 What tools are needed to properly torque drivetrain bolts?
What tools are needed to properly torque drivetrain bolts?
A calibrated torque wrench is essential for accurate torque application. Additionally, a breaker bar, socket set, and thread locker (if specified by the manufacturer) may be required. Ensure all tools are in good condition and properly calibrated.
Environmental Considerations
Temperature, humidity, and seasonal effects on torque specifications
Temperature Effects
Includes: High Heat, Cold Weather, Thermal Cycling
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
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
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
A precision tool for applying accurate torque to drivetrain bolts.
- Adjustable torque settings
- Digital display for precise readings
Torque Angle Gauge
Used to measure the angle of rotation when applying torque-to-yield bolts.
- Magnetic base for easy attachment
- Clear angle markings for accuracy
Thread Locking Compound
Prevents bolts from loosening due to vibrations.
- High-strength formula
- Applicable to critical drivetrain components
Service Procedures
Driveshaft Bolt Torque Procedure
Step-by-step guide to properly torque the driveshaft bolts on a 2018-Present Mercedes CLS.
- Raise the vehicle on a lift and secure it properly.
- Locate the driveshaft bolts connecting the transmission to the differential.
- Clean the bolt threads and apply thread locking compound.
- Tighten the bolts to the specified torque using a digital torque wrench.
- Use a torque angle gauge to apply the final angle rotation if required.
Transmission Mount Bolt Torque Procedure
Detailed instructions for torquing the transmission mount bolts.
- Support the transmission with a jack to relieve pressure on the mounts.
- Remove the old bolts and inspect the threads for damage.
- Install new bolts and tighten them to the specified torque in a crisscross pattern.
- Verify the torque settings with a digital torque wrench.
Technical Service Bulletins
Drivetrain Bolt Loosening Issue
2021-05-15Reports of drivetrain bolts loosening over time due to insufficient torque application.
Resolution: Ensure all drivetrain bolts are torqued to the manufacturer's specifications and use thread locking compound where applicable.
Incorrect Torque Specifications in Manual
2020-11-10Some service manuals contain incorrect torque specifications for drivetrain components.
Resolution: Refer to the updated torque specifications provided by Mercedes-Benz technical support.
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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.