Audi Audi S7 2019-present Drivetrain Bolt Torque Specifications & Fastener Values
Audi Audi S7 2019-present

Audi Audi S7 2019-present Drivetrain Bolt Torque Specifications

This page provides a comprehensive list of torque specifications for various bolts within the drivetrain system of the 2019-Present Audi S7 (C8 generation). Includes specifications for transmission, driveshaft, and differential components.

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

Search Specifications

Search by component name, bolt size, or description

Torque Calculator

Convert between different torque units

Transmission

Torque specifications for various components of the automatic transmission, likely a ZF 8HP series transmission, common in Audi vehicles. These values are critical for ensuring proper operation and preventing leaks.

1

Transmission Oil Pan Bolts

M6 x 1.0
Torque Value
7.4 ft-lbs (10 N·m)
Important Notes
Torque is critical to prevent oil leaks. Use a criss-cross pattern to tighten. Estimated bolt size, confirm before use.
2

Transmission Valve Body Bolts

M6 x 1.0
Torque Value
5.9 ft-lbs (8 N·m)
Important Notes
Proper torque ensures correct valve body operation. Estimated bolt size, confirm before use.
3

Mechatronics Unit Bolts

M6 x 1.0
Torque Value
5.9 ft-lbs (8 N·m)
Important Notes
Correct torque ensures proper electrical contact and sealing. Estimated bolt size, confirm before use.
4

Transmission Housing Bolts (Engine to Transmission)

M12 x 1.5
Important Notes
Critical connection. Tighten in a sequence and angle-tighten to ensure a secure connection and prevent misalignment. Always replace angle bolts. Estimated bolt size, confirm before use.
5

Transmission Mount Bolts (Transmission to Subframe)

M12 x 1.75
Important Notes
Connects the transmission to the chassis. Proper torque is essential for vibration damping and stability. Always replace angle bolts. Estimated bolt size, confirm before use.
6

Transmission Fluid Drain Plug

M18 x 1.5
Torque Value
26 ft-lbs (35 N·m)
Important Notes
Seals the transmission fluid drain opening. Replace crush washer. Estimated bolt size, confirm before use.
7

Transmission Fluid Fill Plug

M18 x 1.5
Torque Value
26 ft-lbs (35 N·m)
Important Notes
Seals the transmission fluid fill opening. Replace crush washer. Estimated bolt size, confirm before use.
8

Output Shaft Flange Bolt (Transmission Output to Driveshaft)

M12 x 1.75
Important Notes
Connects the transmission output to the driveshaft. Proper torque is essential for power transfer and reducing play. Always replace angle bolts. Estimated bolt size, confirm before use.

Driveshafts

Specifications for bolts relating to the driveshafts of the vehicle. These values are critical for the safe and reliable transfer of power to the wheels.

1

Driveshaft to Transmission Flange Bolts

M10 x 1.5
Important Notes
Connects the driveshaft to the transmission output flange. Critical for safe power transfer. Always replace angle bolts. Estimated bolt size, confirm before use.
2

Driveshaft to Differential Flange Bolts

M10 x 1.5
Important Notes
Connects the driveshaft to the differential input flange. Critical for safe power transfer. Always replace angle bolts. Estimated bolt size, confirm before use.
3

Center Support Bearing Mounting Bolts (if applicable)

M8 x 1.25
Torque Value
18 ft-lbs (25 N·m)
Important Notes
Secures the center support bearing. Estimated value and bolt size, confirm before use.

Differential

Torque specifications for various components of the front and rear differentials. These values are critical for differential stability and proper alignment.

1

Differential Housing Bolts

M12 x 1.75
Important Notes
Connects the differential housing to the subframe/chassis. Proper torque is critical for differential stability and proper alignment. Always replace angle bolts. Estimated bolt size, confirm before use.
2

Differential Oil Drain Plug

M14 x 1.5
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Seals the differential oil drain hole. Replace crush washer. Estimated bolt size, confirm before use.
3

Differential Oil Fill Plug

M14 x 1.5
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Seals the differential oil fill hole. Replace crush washer. Estimated bolt size, confirm before use.
4

Differential Input Flange Nut (Pinion Nut)

M20 x 1.5
Important Notes
CRITICAL for preload on the pinion bearings. Requires very accurate measurement and a torque angle gauge. Consult repair manual for specific degrees. MUST be replaced whenever loosened. Estimated bolt size, confirm before use.
5

Differential Output Flange Bolts (axle flange)

M10 x 1.5
Important Notes
Fastens the output flanges to the differential. Critical for power transfer to the axles. Always replace angle bolts. Estimated bolt size, confirm before use.
6

Differential Cover Bolts

M8 x 1.25
Torque Value
18 ft-lbs (25 N·m)
Important Notes
Secures the differential cover. Proper torque is essential for preventing leaks. Estimated bolt size, confirm before use.

Axles

Torque specifications for the axle/halfshaft components. Proper torque values are critical for ensuring safe and reliable power transfer to the wheels.

1

Axle/Halfshaft Inner CV Joint Bolts to Differential Flange

M10 x 1.5
Important Notes
Connects the axle to the differential. Proper torque ensures secure power transfer. Always replace angle bolts. Estimated bolt size, confirm before use.
2

Axle/Halfshaft Outer CV Joint Bolt/Nut (Wheel Hub)

M16 x 1.5
Important Notes
Secures the axle to the wheel hub. CRITICAL for wheel retention and safe driving. Often a one-time-use fastener. ALWAYS REPLACE. Estimated bolt size, confirm before use.

Transfer Case

Torque specifications for transfer case components, relevant for models with quattro all-wheel drive. These are critical for secure mounting and fluid retention.

1

Transfer Case Mounting Bolts

M12 x 1.75
Important Notes
Secures the transfer case to the transmission. Proper torque is critical to avoid vibration and maintain proper alignment. Always replace angle bolts. Estimated bolt size, confirm before use.
2

Transfer Case Fluid Drain Plug

M14 x 1.5
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Seals the transfer case fluid drain hole. Replace crush washer. Estimated bolt size, confirm before use.
3

Transfer Case Fluid Fill Plug

M14 x 1.5
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Seals the transfer case fluid fill hole. Replace crush washer. Estimated bolt size, confirm before use.

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

Why are specific torque specifications important for drivetrain bolts?

Correct torque specifications are crucial for ensuring proper clamping force, preventing bolt failure, and maintaining the integrity of the drivetrain. Under-torquing can cause bolts to loosen, leading to component damage or failure. Over-torquing can stretch or break bolts, potentially causing catastrophic drivetrain issues. Using a calibrated torque wrench is essential for accuracy.

Q2

What happens if I over-torque a drivetrain bolt?

Over-torquing can stretch or yield the bolt, compromising its structural integrity and preload. This can lead to bolt failure, which can have serious consequences within the drivetrain. For example, an over-torqued driveshaft bolt could fracture, causing the driveshaft to detach while driving, resulting in a loss of control and severe damage.

Q3

Can I reuse drivetrain bolts?

It is generally recommended to replace drivetrain bolts, especially torque-to-yield (TTY) bolts, as they are designed to stretch upon tightening and may not achieve proper clamping force if reused. Reusing bolts could lead to loosening or failure under stress, especially given the high loads experienced in the drivetrain. TTY bolts are often identified with specific torque-angle specifications, which require precise measurement of rotation after the initial torque.

Q4

How often should I check my drivetrain bolt torques?

Drivetrain bolt torques should be checked as part of regular maintenance, particularly after any work that involves the removal and reinstallation of components. A good general practice is to check torques after the first 50-100 miles of any drivetrain maintenance and then at your regular maintenance interval (every 5000-10000 miles or per manufacturer recommendations). For example, after replacing the differential oil, ensure the drain and fill plugs are tightened to the correct torque to prevent leaks.

Q5

What are 'torque-to-yield' (TTY) bolts?

Torque-to-yield (TTY) bolts are designed to stretch upon tightening, creating a very precise clamping force. They are typically tightened to a specified torque and then further tightened by a certain angle of rotation. These bolts are not meant to be reused, as their structural integrity is compromised after the initial stretch. Examples include bolts used in driveshaft connections, and it is imperative to replace them with new bolts to ensure proper operation.

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

Torque Wrench (1/2" Drive)

A 1/2" drive torque wrench is essential for accurately tightening drivetrain bolts to the specified torque values.

  • Wide torque range to cover all listed specifications
  • Click-type mechanism for accurate torque application
  • Durable construction for repeated use
Learn more

Torque Wrench (3/8" Drive)

A 3/8" drive torque wrench is useful for smaller bolts and access to tighter areas.

  • Smaller form factor for ease of use in confined areas.
  • Click-type mechanism for accurate torque application
  • Suitable torque range for smaller fasteners.
Learn more

Socket Set (Metric)

A comprehensive set of metric sockets is required to fit the various bolt and nut sizes used in the drivetrain.

  • Includes a variety of sizes (e.g., 10mm, 13mm, 16mm, 18mm, 21mm, etc.)
  • Deep and shallow sockets for different bolt depths
  • Durable construction, preferably chrome vanadium steel
Learn more

Extension Bars

Various lengths of extension bars for reaching difficult access bolts.

  • Various lengths to reach recessed or hard to reach bolts.
  • Durable construction for high torque applications.
Learn more

Universal Joint

Universal joint to reach bolts at an angle.

  • Allows for angle access to bolts
  • Durable construction for high torque applications.
Learn more
Service Procedures

Front Axle Bolt Torque Specification

This procedure outlines the torque specifications for the front axle components, ensuring proper assembly and safe operation.

  • Identify the specific bolt or nut to be tightened.
  • Consult the torque specifications for the identified fastener. See service manual
  • Using the appropriate socket and torque wrench, tighten the bolt or nut to the specified torque value.
  • Verify the torque application by rechecking with the torque wrench.
View full procedure

Rear Axle Bolt Torque Specification

This procedure outlines the torque specifications for the rear axle components, ensuring proper assembly and safe operation.

  • Identify the specific bolt or nut to be tightened.
  • Consult the torque specifications for the identified fastener. See service manual.
  • Using the appropriate socket and torque wrench, tighten the bolt or nut to the specified torque value.
  • Verify the torque application by rechecking with the torque wrench.
View full procedure

Driveshaft Bolt Torque Specification

This procedure outlines the torque specifications for driveshaft components, ensuring proper assembly and safe operation.

  • Identify the specific bolt or nut to be tightened.
  • Consult the torque specifications for the identified fastener. See service manual.
  • Using the appropriate socket and torque wrench, tighten the bolt or nut to the specified torque value.
  • Verify the torque application by rechecking with the torque wrench.
View full procedure

Differential Mounting Bolt Torque Specification

This procedure outlines the torque specifications for differential mounting bolts, ensuring proper assembly and safe operation.

  • Identify the specific bolt or nut to be tightened.
  • Consult the torque specifications for the identified fastener. See service manual.
  • Using the appropriate socket and torque wrench, tighten the bolt or nut to the specified torque value.
  • Verify the torque application by rechecking with the torque wrench.
View full procedure

Transmission Mounting Bolt Torque Specification

This procedure outlines the torque specifications for transmission mounting bolts, ensuring proper assembly and safe operation.

  • Identify the specific bolt or nut to be tightened.
  • Consult the torque specifications for the identified fastener. See service manual.
  • Using the appropriate socket and torque wrench, tighten the bolt or nut to the specified torque value.
  • Verify the torque application by rechecking with the torque wrench.
View full procedure
Technical Service Bulletins

Rear Differential Bolt Loosening Issue

2020-05-15

Some 2019-2020 Audi S7 models may experience rear differential mounting bolt loosening due to insufficient initial torque during factory assembly.

2019-2020

Resolution: Inspect the rear differential mounting bolts for proper torque. Re-torque to the updated specification found in the service manual. Use new bolts if old ones are stretched or damaged.

Driveshaft Bolt Preload

2021-03-20

Some 2019-2021 Audi S7 vehicles have shown abnormal driveshaft wear related to incorrect bolt preload during service.

2019-2021

Resolution: Always replace driveshaft bolts and preload as well as torque them to proper specs. Follow all steps outlined in the service manual

Front Axle Bolt Stretch

2022-08-10

Front axle bolts are one time use, and should be replaced when removing and reinstalling axle assembly. Reuse can lead to unexpected bolt failure.

2019-Present

Resolution: Replace all front axle bolts during reassembly. Follow all service manual instructions for proper torque specifications.

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.

Facebook Contact
15+ Years
Experience
500+ Guides
Guides
50+ Makes
Vehicles
1000+ Solutions
Solutions

Diagnostic

Specialized in advanced diagnostic techniques using modern scan tools and oscilloscopes.

Repair

Expert in both traditional mechanical repairs and modern vehicle systems.

Additional Expertise

Documentation

Created over 500 detailed repair guides and technical documents.

Training

Conducted technical training sessions and contributed to repair databases.

Certifications & Research

Certifications

  • ASE Master Technician Certification
  • Advanced Diagnostic Specialist
  • Hybrid/Electric Vehicle Systems
  • Performance Tuning Expert

Research & Community

Actively researches emerging technologies and contributes to automotive forums.

Legal Disclaimer

Important information about using this content

Always refer to your vehicle's service manual and take appropriate safety precautions when performing any maintenance or repairs.

General Information
The information provided on this website is for general informational purposes only. While we strive to maintain accuracy in our content, all specifications, procedures, and technical information should be verified against your vehicle's official service manual or with the manufacturer directly.
Warranty & Liability

The content on this website is provided "as is" without any representations or warranties, express or implied. We make no representations or warranties regarding the accuracy, completeness, or availability of the information.

We shall not be liable for any direct, indirect, special, or consequential damages arising from the use of information on this website.

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.
Intellectual Property
All content, including text, images, and specifications, is protected by copyright and other intellectual property laws. Any unauthorized use or reproduction is prohibited.

© 2025 Audi Specs. All rights reserved.

Privacy Policy Terms of Service