BMW M6 2012-2018 Drivetrain Bolt Torque Specifications
Comprehensive list of drivetrain bolt torque specifications for the 2012-2018 BMW M6 (F12, F13, and F06 chassis). Includes values for driveshaft, differential, and transmission components.
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
This section covers components that directly connect the engine and transmission, transferring rotational power.
1 Flywheel Bolts
M12 x 1.5
Flywheel Bolts
M12 x 1.5Torque Value
Important Notes
2 Pressure Plate Bolts
M8 x 1.25
Pressure Plate Bolts
M8 x 1.25Important Notes
3 Clutch Slave Cylinder Mounting Bolts
M6 x 1.0
Clutch Slave Cylinder Mounting Bolts
M6 x 1.0Torque Value
Important Notes
Transmission
This section details torque specifications for components directly related to the transmission unit.
1 Transmission Mounting Bolts
M12 x 1.75
Transmission Mounting Bolts
M12 x 1.75Torque Value
Important Notes
2 Transmission Oil Pan Bolts
M6 x 1.0
Transmission Oil Pan Bolts
M6 x 1.0Torque Value
Important Notes
3 Transmission Drain Plug
M18 x 1.5
Transmission Drain Plug
M18 x 1.5Torque Value
Important Notes
4 Transmission Fill Plug
M18 x 1.5
Transmission Fill Plug
M18 x 1.5Torque Value
Important Notes
5 Transmission Output Flange Bolts
M10 x 1.5
Transmission Output Flange Bolts
M10 x 1.5Important Notes
Driveshaft
This section covers components related to the driveshaft (propeller shaft), which transmits power from the transmission to the differential.
1 Propeller/Driveshaft Bolts
M10 x 1.25
Propeller/Driveshaft Bolts
M10 x 1.25Torque Value
Important Notes
Differential
This section details torque specifications for the differential unit, which distributes power to the wheels.
1 Differential Mounting Bolts
M12 x 1.75
Differential Mounting Bolts
M12 x 1.75Torque Value
Important Notes
2 Differential Drain Plug
M18 x 1.5
Differential Drain Plug
M18 x 1.5Torque Value
Important Notes
3 Differential Fill Plug
M18 x 1.5
Differential Fill Plug
M18 x 1.5Torque Value
Important Notes
4 Differential Cover Bolts
M8 x 1.25
Differential Cover Bolts
M8 x 1.25Torque Value
Important Notes
5 Differential Output Flange Bolts
M10 x 1.5
Differential Output Flange Bolts
M10 x 1.5Important Notes
Axle Shafts
This section contains torque specifications for the axle shafts (half shafts) and related CV joint components.
1 Drive Axle/Half Shaft Bolts
M10 x 1.5
Drive Axle/Half Shaft Bolts
M10 x 1.5Torque Value
Important Notes
2 CV Joint/Axle Nut
M24 x 1.5
CV Joint/Axle Nut
M24 x 1.5Important Notes
Transfer Case
This section covers components related to the transfer case, which is responsible for distributing power to all wheels in a four-wheel-drive system.
1 Transfer Case Mounting Bolts
M12 x 1.75
Transfer Case Mounting Bolts
M12 x 1.75Torque Value
Important Notes
2 Transfer Case Drain Plug
M18 x 1.5
Transfer Case Drain Plug
M18 x 1.5Torque Value
Important Notes
3 Transfer Case Fill Plug
M18 x 1.5
Transfer Case Fill Plug
M18 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 Why are correct torque specifications important for drivetrain bolts?
Why are correct torque specifications important for drivetrain bolts?
Using the correct torque ensures proper clamping force, preventing bolts from loosening due to vibration and stress. Under-torqued bolts can loosen, leading to component failure, while over-torqued bolts can stretch or break, causing damage to both the bolt and the mating part. For example, overtightening the bolts on the driveshaft could damage the threads on the flange or cause the joint to bind, leading to premature wear.
Q2 What type of tool should I use to tighten drivetrain bolts?
What type of tool should I use to tighten drivetrain bolts?
A calibrated torque wrench is essential for achieving accurate torque specifications. Avoid using impact wrenches, as they often over-tighten bolts and can damage components. For example, using an impact gun on the transmission mounting bolts may result in the bolts failing prematurely.
Q3 Should I use new bolts when working on the drivetrain?
Should I use new bolts when working on the drivetrain?
In many cases, yes. BMW often uses torque-to-yield bolts, which are designed to stretch slightly when tightened. These bolts are intended for one-time use and should be replaced with new ones when removed. Using old torque-to-yield bolts can lead to improper clamping and component failure. For example, replacing the driveshaft bolts with new ones after removing the old ones is crucial for proper reassembly.
Q4 What is the purpose of thread-locking compounds on drivetrain bolts?
What is the purpose of thread-locking compounds on drivetrain bolts?
Thread-locking compounds, like Loctite, help to prevent bolts from loosening due to vibration. This is especially important in high-stress areas of the drivetrain, such as the differential or transmission mounts. Apply thread locker where the manufacturer specifies, and allow it to cure fully before driving the vehicle. For example, Loctite is sometimes used on the bolts holding the rear differential to the subframe.
Q5 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 after any service or repair involving their removal. You should also perform a visual inspection at each oil change for any signs of loosening or damage. If you experience any unusual noises or vibrations, have the torque specs checked promptly. For example, after replacing the guibo (flex disc), check the torque specs on its bolts after about 100 miles.
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
Torque Wrench (1/2" Drive)
A high-quality torque wrench is essential for accurately tightening bolts to specification, preventing over or under-tightening.
- Click-type mechanism for accurate torque setting
- Wide torque range to accommodate various drivetrain bolts
- Durable construction for long-term use
Torque Wrench (3/8" Drive)
A smaller 3/8" torque wrench is useful for smaller, less torqued drivetrain bolts.
- Click-type mechanism for accurate torque setting
- Lower torque range than 1/2" drive
- Durable construction for long-term use
Socket Set (Metric)
A complete set of metric sockets is required to fit the various bolt and nut sizes found throughout the drivetrain.
- Wide range of metric sizes
- Various socket depths and styles (standard and deep)
- Durable chrome vanadium steel construction
Universal Joint Adapter
A universal joint adapter allows access to bolts in tight or angled locations.
- Durable steel construction
- Provides flexible access
- Fits both 1/2" and 3/8" drives
Extension Bars
Extension bars provide extra reach to access recessed bolts and nuts.
- Various lengths available
- Durable steel construction
- Fits both 1/2" and 3/8" drives
Service Procedures
Driveshaft Bolt Torque Procedure
This procedure outlines the correct steps for tightening the driveshaft bolts to the specified torque. Always use new bolts as they are stretch bolts.
- 1. Clean the threads of the bolts and mating surfaces.
- 2. Install new driveshaft bolts by hand, ensuring they are correctly aligned with the flange.
- 3. Tighten bolts to the initial specified torque, in a star pattern.
- 4. Tighten bolts to the final specified torque, in a star pattern.
- 5. Verify all bolts are tightened to the correct torque using a calibrated torque wrench.
Differential Mounting Bolt Torque Procedure
This procedure outlines the correct steps for tightening the differential mounting bolts to the specified torque. Always use new bolts as they are stretch bolts.
- 1. Clean the threads of the bolts and mating surfaces.
- 2. Install new differential mounting bolts by hand, ensuring they are correctly aligned with the chassis.
- 3. Tighten bolts to the initial specified torque, in a star pattern.
- 4. Tighten bolts to the final specified torque, in a star pattern.
- 5. Verify all bolts are tightened to the correct torque using a calibrated torque wrench.
Transmission Mount Bolt Torque Procedure
This procedure outlines the correct steps for tightening the transmission mount bolts to the specified torque. Always use new bolts as they are stretch bolts.
- 1. Clean the threads of the bolts and mating surfaces.
- 2. Install new transmission mount bolts by hand, ensuring they are correctly aligned with the subframe.
- 3. Tighten bolts to the initial specified torque, in a star pattern.
- 4. Tighten bolts to the final specified torque, in a star pattern.
- 5. Verify all bolts are tightened to the correct torque using a calibrated torque wrench.
Technical Service Bulletins
Driveshaft Bolt Loosening Issue
2016-04-15Some 2012-2016 M6 models have experienced driveshaft bolt loosening due to improper initial torque specification. This may cause vibrations and potential damage.
Resolution: Inspect and replace all driveshaft bolts with new ones, torquing them to the updated specification. Check for vibrations after repair. Do not reuse old driveshaft bolts.
Differential Mounting Bolt Corrosion
2017-08-22Certain M6 models exposed to harsh road conditions have experienced corrosion on the differential mounting bolts, leading to potential loosening and noise issues. Always use new bolts during replacement.
Resolution: Inspect differential mounting bolts for corrosion. Replace any corroded bolts using the updated torque specifications. Apply anti-seize to new bolts during installation in regions with high road salt usage.
Transmission Mount Bolt Failure
2015-11-10Isolated incidents of premature failure of transmission mounting bolts have been reported. The bolts are stretch bolts and should not be reused. Replace when removed.
Resolution: Inspect the transmission mount bolts. Replace all bolts with new ones using the revised torque procedure to resolve. Do not reuse old transmission mount bolts.
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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.
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- If you're unsure about any procedure, consult a qualified professional mechanic.