Audi Audi S4 2009-2016 Suspension Bolt Torque Specifications
Comprehensive list of torque specifications for all suspension bolts on the 2009-2016 Audi S4 (B8 platform). 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 Suspension
Torque specifications for various components of the front suspension system including control arms, struts, and anti-roll bar.
1 Upper Control Arm to Strut Tower Bolts
M12 x 1.5
Upper Control Arm to Strut Tower Bolts
M12 x 1.5Important Notes
2 Lower Control Arm to Subframe Bolts
M14 x 1.5
Lower Control Arm to Subframe Bolts
M14 x 1.5Important Notes
3 Lower Control Arm Ball Joint to Steering Knuckle Bolt
M12 x 1.5
Lower Control Arm Ball Joint to Steering Knuckle Bolt
M12 x 1.5Important Notes
4 Anti-Roll Bar (Sway Bar) Link to Strut Bolts
M10 x 1.5
Anti-Roll Bar (Sway Bar) Link to Strut Bolts
M10 x 1.5Torque Value
Important Notes
5 Anti-Roll Bar (Sway Bar) Bracket Bolts to Subframe
M10 x 1.5
Anti-Roll Bar (Sway Bar) Bracket Bolts to Subframe
M10 x 1.5Torque Value
Important Notes
6 Front Strut Pinch Bolt
M14 x 1.5
Front Strut Pinch Bolt
M14 x 1.5Important Notes
7 Strut Mount Bolts to Body
M8 x 1.25
Strut Mount Bolts to Body
M8 x 1.25Torque Value
Important Notes
8 Brake Caliper Bracket Bolts
M14 x 1.5
Brake Caliper Bracket Bolts
M14 x 1.5Torque Value
Important Notes
9 Brake Caliper Guide Pin Bolts
M8 x 1.25
Brake Caliper Guide Pin Bolts
M8 x 1.25Torque Value
Important Notes
Rear Suspension
Torque specifications for various components of the rear suspension system including control arms, shocks, and anti-roll bar.
1 Upper Control Arm to Body Bolts
M10 x 1.5
Upper Control Arm to Body Bolts
M10 x 1.5Important Notes
2 Lower Control Arm to Subframe Bolts
M14 x 1.5
Lower Control Arm to Subframe Bolts
M14 x 1.5Important Notes
3 Lower Control Arm Ball Joint to Wheel Carrier
M12 x 1.5
Lower Control Arm Ball Joint to Wheel Carrier
M12 x 1.5Important Notes
4 Anti-Roll Bar (Sway Bar) Link to Control Arm Bolts
M10 x 1.5
Anti-Roll Bar (Sway Bar) Link to Control Arm Bolts
M10 x 1.5Torque Value
Important Notes
5 Anti-Roll Bar (Sway Bar) Bracket Bolts to Body
M10 x 1.5
Anti-Roll Bar (Sway Bar) Bracket Bolts to Body
M10 x 1.5Torque Value
Important Notes
6 Rear Shock Absorber Lower Bolt
M14 x 1.5
Rear Shock Absorber Lower Bolt
M14 x 1.5Important Notes
7 Rear Shock Absorber Upper Mount Bolts
M8 x 1.25
Rear Shock Absorber Upper Mount Bolts
M8 x 1.25Torque Value
Important Notes
8 Rear Wheel Carrier (Hub) Bolt
M14 x 1.5
Rear Wheel Carrier (Hub) Bolt
M14 x 1.5Important Notes
9 Toe Adjustment Link Bolts
M10 x 1.5
Toe Adjustment Link Bolts
M10 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 suspension bolts?
Why are correct torque specifications important for suspension bolts?
Correct torque is crucial for maintaining the structural integrity and performance of your Audi S4's suspension. Over-tightening can stretch or break bolts and damage components, leading to premature wear or failure. Under-tightening can cause bolts to loosen, resulting in instability, noise, and potentially dangerous situations, such as loss of control. Proper torque ensures optimal clamping force, preventing movement and maintaining proper alignment.
Q2 What happens if I overtighten a suspension bolt?
What happens if I overtighten a suspension bolt?
Overtightening suspension bolts can lead to several problems. The most common is bolt stretching or shearing, weakening the bolt and potentially causing it to break under stress. It can also damage the threads in the mounting component, requiring costly repairs, and may crush bushings, leading to poor suspension performance and premature wear. This is why a torque wrench is a must for suspension work.
Q3 Do I need to use new bolts when working on the suspension?
Do I need to use new bolts when working on the suspension?
It's highly recommended to replace single-use stretch bolts when working on the suspension. These bolts are designed to deform slightly upon tightening, and they lose their clamping force if reused. While many suspension bolts can be reused, bolts that have been heavily corroded or those that have been removed after reaching their service life should be replaced. Always consult a repair manual for your specific vehicle as some bolts should always be replaced.
Q4 Do I need to torque suspension bolts with the vehicle on the ground or in the air?
Do I need to torque suspension bolts with the vehicle on the ground or in the air?
Generally, many suspension bolts, particularly those that connect to bushings (e.g., control arm bolts), should be torqued with the vehicle's suspension at its normal ride height. This can be achieved by having the vehicle on the ground or using a drive-on lift that allows the wheels to be supported. Torquing these bolts while the suspension is hanging can cause the bushings to be in a pre-loaded state, which can lead to premature wear and incorrect suspension geometry. Bolts connecting metal-to-metal may be torqued with the suspension unloaded. Always refer to the repair manual for the specific torque procedures for each component.
Q5 What kind of torque wrench should I use?
What kind of torque wrench should I use?
A calibrated torque wrench is essential for accurate tightening. For suspension work, a 1/2-inch drive torque wrench with a range covering the required torque specifications is most common. Consider purchasing a click-type or digital torque wrench. Click-type wrenches require regular calibration. Digital wrenches can be more precise, and some can store and recall specific torque values. Always follow the manufacturer's recommendations and recalibrate your torque wrench according to the prescribed interval.
Q6 How do I find the correct torque specs for my specific vehicle and component?
How do I find the correct torque specs for my specific vehicle and component?
The best way is to consult the official repair manual for your 2009-2016 Audi S4. This manual will provide detailed torque specifications for every bolt in the suspension system. You can also find this information in reputable online databases like the Mitchell ProDemand or Alldata. Avoid relying on generalized torque specifications and double check your specs.
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
A calibrated torque wrench is essential for tightening suspension bolts to the manufacturer's specified torque values.
- 1/2 inch drive
- Ability to measure torque in Newton-meters (Nm)
Socket Set
A set of sockets, including common sizes for suspension bolts (typically 13mm, 16mm, 18mm, 21mm, 24mm).
- Metric sizing
- Deep and standard sockets
Wrench Extensions
Extensions provide necessary reach for some suspension bolts.
- Various lengths for different reach requirements
- 1/2 inch drive
Triple Square Socket Set
Triple square sockets are required for some of the suspension bolts, such as those securing the strut to the wheel bearing housing.
- M8, M10, M12, M14 and M16 sizes
- Various lengths
Ball Joint Separator
Tool used to separate ball joints from control arms.
- Universal fit
- Adjustable
Service Procedures
Front Upper Control Arm Bolt Torque Procedure
This procedure outlines the steps for tightening the upper control arm bolts to the correct torque specifications.
- Loosen all upper control arm bolts.
- With vehicle weight on the suspension (wheels on the ground), tighten the inner upper control arm bolts to 40 Nm + 90 degrees.
- With vehicle weight on the suspension (wheels on the ground), tighten the outer upper control arm bolts to 40 Nm + 90 degrees.
Front Lower Control Arm Bolt Torque Procedure
This procedure outlines the steps for tightening the lower control arm bolts to the correct torque specifications.
- Loosen all lower control arm bolts.
- With vehicle weight on the suspension (wheels on the ground), tighten the rear lower control arm bolts to 70 Nm + 90 degrees.
- With vehicle weight on the suspension (wheels on the ground), tighten the front lower control arm bolts to 70 Nm + 90 degrees.
Front Strut to Wheel Bearing Housing Bolt Torque Procedure
This procedure outlines the steps for tightening the strut to wheel bearing housing bolts to the correct torque specifications.
- Loosen the strut to wheel bearing housing bolts.
- Tighten the strut to wheel bearing housing bolts using a triple square socket to 70 Nm + 90 degrees.
Rear Upper Control Arm Bolt Torque Procedure
This procedure outlines the steps for tightening the rear upper control arm bolts to the correct torque specifications.
- Loosen all rear upper control arm bolts.
- With vehicle weight on the suspension (wheels on the ground), tighten the inner upper control arm bolts to 40 Nm + 90 degrees.
- With vehicle weight on the suspension (wheels on the ground), tighten the outer upper control arm bolts to 40 Nm + 90 degrees.
Rear Lower Control Arm Bolt Torque Procedure
This procedure outlines the steps for tightening the rear lower control arm bolts to the correct torque specifications.
- Loosen all rear lower control arm bolts.
- With vehicle weight on the suspension (wheels on the ground), tighten the lower control arm bolts to 70 Nm + 90 degrees.
Rear Shock Absorber Bolt Torque Procedure
This procedure outlines the steps for tightening the rear shock absorber bolts to the correct torque specifications.
- Loosen all rear shock absorber bolts.
- Tighten the upper shock absorber bolt to 60 Nm.
- With vehicle weight on the suspension (wheels on the ground), tighten the lower shock absorber bolt to 90 Nm + 90 degrees.
Technical Service Bulletins
Suspension Bolt Loosening After Service
2013-05-10Some customers have reported suspension bolts loosening after servicing. This bulletin highlights the importance of using the correct torque specifications and replacement of stretch bolts.
Resolution: Always replace stretch bolts, always torque bolts with the vehicle weight on the suspension, and use calibrated torque wrenches.
Front Suspension Creaking Noise
2014-09-15Front suspension creaking noise can sometimes be caused by improper torqueing of control arm bolts. Proper tightening of suspension bolts is crucial to ensure proper function and reduce the possibility of suspension issues.
Resolution: Re-torque all front control arm bolts to spec, as well as properly lubricating relevant bushings.
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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.