Audi Audi A4 2009-2016 AL450 Transmission Transmission Torque Specifications & Bolt Torque Values
Audi Audi A4 2009-2016

Audi Audi A4 2009-2016 AL450 Transmission Torque Specifications

This page provides a comprehensive list of torque specifications for all bolts related to the AL450 transmission used in the 2009-2016 Audi A4 B8 generation, including housing, valve body, and pan bolts.

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

Al450-transmission Mounting

Torque specifications for mounting the AL450 transmission to the engine and chassis.

1

Transmission Mounting Bolts

M12 x 1.75
Torque Value
44 ft-lbs (60 N·m)
Important Notes
These bolts secure the transmission to the engine block and/or the subframe. Ensure correct alignment before final tightening.
2

Transmission Bell Housing Bolts (Engine Side)

M10 x 1.5
Torque Value
37 ft-lbs (50 N·m)
Important Notes
Estimated torque value. These bolts secure the bell housing to the engine block. Ensure correct alignment before tightening.

Al450-transmission Internal

Torque specifications for internal components within the AL450 transmission.

1

Valve Body Bolts

M6 x 1.0
Torque Value
0.74 ft-lbs (10 N·m)
Important Notes
Use a proper torque pattern and do not overtighten. In-lbs converted to ft-lbs for display.
2

Transmission Case Bolts (split case if applicable)

M8 x 1.25
Torque Value
18 ft-lbs (25 N·m)
Important Notes
Estimated value. Tighten in a cross pattern to avoid warping the case.
3

Torque Converter to Flexplate Bolts

M8 x 1.25
Torque Value
44 ft-lbs (60 N·m)
Important Notes
Estimated torque value, may vary slightly based on bolt grade. Tighten evenly in a star pattern.

Al450-transmission External

Torque specifications for external components of the AL450 transmission.

1

Transmission Oil Pan Bolts

M6 x 1.0
Torque Value
0.74 ft-lbs (10 N·m)
Important Notes
In-lbs converted to ft-lbs for display. Use a new gasket and tighten in a cross pattern.
2

Transmission Fluid Drain/Fill Plugs

M18 x 1.5
Torque Value
44 ft-lbs (60 N·m)
Important Notes
Ensure proper sealing. Replace sealing washer or o-ring if necessary.
3

Drive Axle/Half Shaft Bolts

M10 x 1.5
Torque Value
89 ft-lbs (120 N·m)
Important Notes
These are often single-use bolts. Replace with new bolts if specified. Ensure correct seating of the axle flange.
4

Transmission Cooler Line Fittings

M16 x 1.5 (estimated)
Torque Value
15 ft-lbs (20 N·m)
Important Notes
Estimated value. Do not over-tighten. May vary with size of fitting. Replace o-rings if necessary.
5

Transmission Range Sensor/Position Sensor Bolt

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Do not over-tighten. Ensure sensor is seated correctly.

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 is using the correct torque specifications important for the AL450 transmission?

Using the correct torque specifications is critical for the proper function and longevity of your AL450 transmission. Over-tightening bolts can lead to thread stripping, component damage, and distortion of mating surfaces, potentially causing leaks and premature failure. Under-tightening can cause bolts to loosen over time, leading to leaks, vibrations, and eventually, component separation. Proper torque ensures even clamping force and a secure, leak-free seal.

Q2

What happens if I over-tighten the transmission pan bolts?

Over-tightening transmission pan bolts on the AL450 can deform the pan, potentially causing leaks, especially around the gasket. It can also damage the threads in the transmission case, necessitating costly repairs. In severe cases, it can lead to cracking the transmission housing. Always use a torque wrench and adhere to the specified torque values to prevent this.

Q3

Do I need to replace bolts when working on the AL450 transmission?

While not always mandatory, it is generally good practice to replace torque-to-yield bolts or bolts that have been removed multiple times, as they can weaken over time. Specifically, the bolts securing the valve body or mechatronic unit in the AL450 transmission are often recommended for replacement because of the criticality of the component and the potential for leaks if clamping force is compromised. Refer to the specific repair manual for guidance.

Q4

What type of lubricant should I use when installing bolts on the AL450 transmission?

Typically, you should not use any lubricant on the threads of the bolts unless the service manual explicitly states otherwise. Clean threads are typically adequate. If the manual advises using a lubricant, make absolutely certain to use the specified type. Using an incorrect lubricant can impact the final bolt torque achieved, as it changes friction between the threads. Applying any lubricant incorrectly can significantly affect bolt torque readings, making it crucial to follow the specific recommendations for your transmission.

Q5

How often should I check the torque on transmission components after a repair on the AL450?

After completing a repair on the AL450 transmission, it's a best practice to re-check the torque on all fasteners after a short run-in period, typically after driving a few hundred kilometers or within the first week of driving. This is because bolts may settle or stretch slightly. If you hear any unusual noises such as clicking, rattling, or whining, or notice leaks, then an immediate torque inspection is required.

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 calibrated torque wrench is essential for accurately tightening bolts to specification.

  • Wide torque range to cover all fasteners
  • Accurate and repeatable measurements
Learn more

Torque Wrench (3/8" drive)

A smaller drive torque wrench for smaller fasteners in the transmission system

  • Smaller range for precision
  • Easier handling for smaller fasteners
Learn more

Socket Set (1/2" and 3/8" drive)

A comprehensive set of sockets to fit the various bolt heads on the transmission.

  • Metric sizes to match all transmission bolts
  • Various depths and extensions
Learn more

Extension Bars (1/2" and 3/8" drive)

Used to reach recessed bolts on the transmission assembly.

  • Provides clearance when access is difficult
  • Allows for proper torque application
Learn more

Universal Joint (1/2" and 3/8" drive)

Allows for angled application of the torque wrench in tight spaces.

  • Enables access to awkward bolt locations
  • Maintains torque accuracy
Learn more
Service Procedures

AL450 Transmission Oil Pan Bolt Torque Procedure

Procedure for correctly tightening the oil pan bolts on the AL450 transmission.

  • Clean all mating surfaces of the oil pan and transmission case.
  • Install new oil pan gasket.
  • Install the oil pan and start all bolts by hand to finger tight.
  • Tighten bolts in a star pattern to 8 Nm (71 in-lbs).
  • Final tighten bolts in the same star pattern to 15 Nm (11 ft-lbs).
View full procedure

AL450 Transmission Mechatronic Unit Bolt Torque Procedure

Procedure for correctly tightening the mechatronic unit bolts on the AL450 transmission.

  • Ensure the mechatronic unit is properly aligned and seated.
  • Start all mechatronic unit bolts by hand to finger tight.
  • Tighten bolts in a criss-cross pattern to 5 Nm (44 in-lbs)
  • Final tighten bolts in the same criss-cross pattern to 10 Nm (89 in-lbs).
View full procedure

AL450 Transmission Bellhousing Bolt Torque Procedure

Procedure for correctly tightening the bellhousing bolts on the AL450 transmission.

  • Ensure the bellhousing is flush with the engine block.
  • Start all bellhousing bolts by hand to finger tight.
  • Tighten bolts in a star pattern to 30 Nm (22 ft-lbs).
  • Final tighten bolts in the same star pattern to 60 Nm (44 ft-lbs).
View full procedure
Technical Service Bulletins

Increased Risk of Leaking from AL450 Transmission Oil Pan

2012-05-10

Some 2009-2012 Audi A4 models with the AL450 transmission have experienced oil pan leaks due to insufficient torque during initial assembly.

2009-2012

Resolution: Re-torque the oil pan bolts to 15 Nm (11 ft-lbs) in a star pattern, using a new gasket if leakage is evident. Ensure all surfaces are clean before reinstalling.

Mechatronic Unit Bolt Loosening and Resulting Fault Codes

2014-02-15

A small number of 2013-2014 Audi A4 vehicles with the AL450 transmission are reporting transmission fault codes due to slightly loose mechatronic unit bolts.

2013-2014

Resolution: Verify correct torque of 10 Nm (89 in-lbs) on all mechatronic unit bolts using a criss-cross tightening sequence. Inspect wiring harnesses for damage.

About the Author

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Alan Montanye - Automotive Technical Specialist
ASE

Alan Montanye

Automotive Technical Specialist

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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.
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