Audi Audi S4 2016-present Suspension Bolt Torque Specifications
Comprehensive torque specifications for all suspension bolts on the 2016-Present Audi S4 (B9 and B9.5 generation). Includes front and rear suspension 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
Front Strut
Torque specifications for components related to the front strut assembly, connecting the strut to the steering knuckle and chassis.
1 Front Strut to Steering Knuckle Bolts
M14 x 1.5
Front Strut to Steering Knuckle Bolts
M14 x 1.5Important Notes
2 Front Strut Mount to Body Bolts
M8 x 1.25
Front Strut Mount to Body Bolts
M8 x 1.25Torque Value
Important Notes
Front Control Arms
Torque specifications for the front upper and lower control arms, crucial for maintaining suspension geometry.
1 Front Upper Control Arm to Body Bolts (Inner)
M12 x 1.5
Front Upper Control Arm to Body Bolts (Inner)
M12 x 1.5Important Notes
2 Front Upper Control Arm to Steering Knuckle Nut (Outer Ball Joint)
M12 x 1.5
Front Upper Control Arm to Steering Knuckle Nut (Outer Ball Joint)
M12 x 1.5Important Notes
3 Front Lower Control Arm to Subframe Bolts (Inner)
M14 x 1.5
Front Lower Control Arm to Subframe Bolts (Inner)
M14 x 1.5Important Notes
4 Front Lower Control Arm Ball Joint to Steering Knuckle Nut (Outer)
M14 x 1.5
Front Lower Control Arm Ball Joint to Steering Knuckle Nut (Outer)
M14 x 1.5Torque Value
Important Notes
Front Sway Bar
Torque specifications for the front sway bar end links, connecting the sway bar to the strut and control arm.
1 Front Sway Bar Link to Strut Bolt
M10 x 1.5
Front Sway Bar Link to Strut Bolt
M10 x 1.5Torque Value
Important Notes
2 Front Sway Bar Link to Sway Bar Bolt
M10 x 1.5
Front Sway Bar Link to Sway Bar Bolt
M10 x 1.5Torque Value
Important Notes
Front Sensors
Torque specification for front speed sensor.
1 Front Wheel Speed Sensor Bolt
M6 x 1
Front Wheel Speed Sensor Bolt
M6 x 1Torque Value
Important Notes
Rear Shock
Torque specifications for the rear shock absorber mounting bolts, connecting the shock to the chassis and suspension.
1 Rear Shock Absorber Lower Bolt
M14 x 1.5
Rear Shock Absorber Lower Bolt
M14 x 1.5Important Notes
2 Rear Shock Absorber Upper Bolts
M10 x 1.5
Rear Shock Absorber Upper Bolts
M10 x 1.5Torque Value
Important Notes
Rear Control Arms
Torque specifications for rear upper and lower control arms, crucial for rear suspension geometry.
1 Rear Upper Control Arm to Body Bolts (Inner)
M12 x 1.5
Rear Upper Control Arm to Body Bolts (Inner)
M12 x 1.5Important Notes
2 Rear Upper Control Arm to Knuckle Nut (Outer Ball Joint)
M12 x 1.5
Rear Upper Control Arm to Knuckle Nut (Outer Ball Joint)
M12 x 1.5Important Notes
3 Rear Lower Control Arm to Subframe Bolts (Inner)
M14 x 1.5
Rear Lower Control Arm to Subframe Bolts (Inner)
M14 x 1.5Important Notes
4 Rear Lower Control Arm to Knuckle Nut (Outer Ball Joint)
M14 x 1.5
Rear Lower Control Arm to Knuckle Nut (Outer Ball Joint)
M14 x 1.5Torque Value
Important Notes
Rear Sway Bar
Torque specifications for the rear sway bar end links, connecting the sway bar to the control arm or knuckle.
1 Rear Sway Bar Link to Control Arm/Knuckle Bolt
M10 x 1.5
Rear Sway Bar Link to Control Arm/Knuckle Bolt
M10 x 1.5Torque Value
Important Notes
2 Rear Sway Bar Link to Sway Bar Bolt
M10 x 1.5
Rear Sway Bar Link to Sway Bar Bolt
M10 x 1.5Torque Value
Important Notes
Rear Sensors
Torque specification for rear wheel speed sensor.
1 Rear Wheel Speed Sensor Bolt
M6 x 1
Rear Wheel Speed Sensor Bolt
M6 x 1Torque Value
Important Notes
Subframe
Torque specifications for subframe mounting bolts.
1 Subframe to Body Bolts
M14 x 1.5
Subframe to Body Bolts
M14 x 1.5Important 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 is it important to use the correct torque specifications for suspension bolts?
Why is it important to use the correct torque specifications for suspension bolts?
Using the correct torque specifications is critical for the safety and performance of your vehicle's suspension. Under-tightening bolts can lead to components shifting or loosening, resulting in instability and potential failure. Over-tightening can damage bolts, threads, or mounting points, causing premature wear and potential component failure. Proper torque ensures the correct clamping force, maintaining the integrity of the suspension system.
Q2 What tools do I need to properly torque suspension bolts?
What tools do I need to properly torque suspension bolts?
You will need a torque wrench with an appropriate range for the specified torque values. It is highly recommended to use a calibrated torque wrench for accurate measurements. You may also need various sockets, extensions, and potentially universal joints to reach all the bolts. Always consult the vehicle's service manual for recommended tools and sizes.
Q3 Should I replace suspension bolts every time I remove them?
Should I replace suspension bolts every time I remove them?
Some suspension bolts are one-time use and are designed to stretch upon tightening. It's crucial to consult your vehicle's repair manual or a reputable source for specific recommendations. Some bolts may be designed to be reusable, however, always inspect them for any damage or signs of wear, and replace if in doubt. Ignoring these warnings can lead to bolt failure.
Q4 What if I don't have a torque wrench?
What if I don't have a torque wrench?
A torque wrench is essential for proper suspension work. Attempting to tighten bolts 'by feel' is highly discouraged and extremely unsafe. Using guesswork could easily lead to over or under torquing the bolts. If you do not own a torque wrench, rent or borrow one, or consider taking your car to a professional mechanic. Safety must always come first.
Q5 What does 'Nm' and 'ft-lbs' mean and how can I convert them?
What does 'Nm' and 'ft-lbs' mean and how can I convert them?
'Nm' stands for Newton-meters, and 'ft-lbs' stands for foot-pounds; they are both units of torque measurement. Newton-meters (Nm) are common in European car specifications (like Audi), while foot-pounds (ft-lbs) are commonly used in North America. A useful conversion is: 1 ft-lb = 1.356 Nm. So, if you see a torque spec of 100 Nm, it's approximately 73.7 ft-lbs.
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 calibrated torque wrench is essential for applying precise torque to suspension bolts.
- Click-type or digital readout
- Range covering 10-200 ft-lbs (approximate range needed for most suspension bolts)
Torque Wrench (3/8" Drive)
A smaller torque wrench for lower torque applications, typically used for smaller bolts in the suspension system.
- Click-type or digital readout
- Range covering 5-75 ft-lbs (approximate range for smaller fasteners)
Socket Set (Metric)
A comprehensive set of metric sockets, including standard and deep sockets, is necessary to fit various bolt heads in the suspension.
- Variety of sizes (e.g., 10mm, 13mm, 16mm, 18mm, 21mm)
- Both standard and deep socket options
Wrench Set (Metric)
A set of metric wrenches for holding nuts and bolts when torquing or when a socket cannot be used.
- Variety of sizes (matching your socket set)
- Combination or open-end options
Extension Bars
Extension bars allow you to reach bolts in difficult-to-access areas.
- Various lengths (3 inch, 6 inch, 10 inch)
- 1/2" and 3/8" drive options
Universal Joint/Swivel Adapter
Allows you to apply torque at an angle when a straight approach is not possible.
- 1/2" and 3/8" drive options
- Durable construction
Anti-Seize Lubricant
Apply anti-seize to fasteners to prevent corrosion and facilitate future removal.
- High-temperature rating
- Prevents galling
Service Procedures
Front Strut Assembly Removal and Installation
Procedure for removing and reinstalling the front strut assembly on the Audi S4. This procedure includes the torque specifications for fasteners related to the strut.
- Loosen the wheel lug bolts.
- Raise and support the vehicle on jack stands.
- Remove the wheel.
- Disconnect the ABS sensor wire.
- Disconnect the sway bar end link.
- Remove the strut pinch bolt and strut pinch clamp.
- Remove the three upper strut mount bolts.
- Carefully remove the strut assembly.
- Reinstall the strut assembly in reverse order.
- Torque all fasteners to their specified torques.
Rear Shock Absorber Removal and Installation
Procedure for removing and reinstalling the rear shock absorbers on the Audi S4. Includes torquing specifications for all related bolts and nuts.
- Loosen the wheel lug bolts.
- Raise and support the vehicle on jack stands.
- Remove the wheel.
- Disconnect the lower shock bolt.
- Remove the upper shock mounting bolts.
- Carefully remove the shock absorber.
- Reinstall the shock absorber in reverse order.
- Torque all fasteners to their specified torques.
Control Arm Removal and Installation
Procedure for removing and reinstalling a control arm. Includes torque specs for associated bolts and nuts.
- Loosen the wheel lug bolts.
- Raise and support the vehicle on jack stands.
- Remove the wheel.
- Disconnect the control arm from the steering knuckle.
- Remove the control arm mounting bolts from the subframe.
- Carefully remove the control arm.
- Reinstall the control arm in reverse order.
- Torque all fasteners to their specified torques.
Sway Bar End Link Removal and Installation
Procedure for removing and reinstalling the sway bar end links. Includes correct torque specs.
- Loosen the wheel lug bolts.
- Raise and support the vehicle on jack stands.
- Remove the wheel.
- Remove the sway bar end link bolts.
- Remove the sway bar end link.
- Install the new end link in the reverse order.
- Torque all fasteners to the specified torques.
Technical Service Bulletins
Potential for Front Strut Pinch Bolt Corrosion
2019-07-15Some vehicles may exhibit corrosion on the front strut pinch bolts, leading to difficulty in removal and potential damage. This issue can affect torque readings when re-torquing.
Resolution: Inspect pinch bolts for corrosion. If corrosion is present, clean or replace the bolt. Apply anti-seize to prevent future issues. Ensure correct torque specification is applied.
Rear Control Arm Bolt Loosening
2021-03-01Reports indicate the possibility of rear control arm bolts loosening after several thousand miles. It is recommended to inspect and re-torque these bolts.
Resolution: Inspect and re-torque rear control arm bolts to the manufacturers' specifications. Apply thread locking compound during reinstallation to minimize risk of future loosening. Conduct checks periodically.
Sway Bar End Link Bolt Fatigue
2023-11-10Some Audi S4 models have exhibited fatigue issues with sway bar end link bolts after high-performance driving. Careful torque application is key.
Resolution: Inspect end link bolts for stretching or damage. Replace if needed. Use a new, high-quality bolt with correct torque. Re-torque after the first 500 miles following installation.
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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.