Buick Regal 2018-present Drivetrain Bolt Torque Specifications & Fastener Values
Buick Regal 2018-present

Buick Regal 2018-present Drivetrain Bolt Torque Specifications

Detailed torque specifications for various drivetrain bolts on the 2018-Present Buick Regal, including 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 components related to the transmission or transaxle assembly, ensuring proper mounting and sealing.

1

Transmission Mounting Bolts (Engine Side)

M12 x 1.75
Torque Value
52 ft-lbs (70 N·m)
Important Notes
Secures the transmission to the engine block. Proper torque ensures alignment and prevents vibrations. Estimated value.
2

Transmission Mount Bolts (Subframe Side)

M12 x 1.75
Important Notes
Secures transmission mounts to the subframe. Proper torque plus angle prevents movement. Estimated value.
3

Transmission Pan Bolts

M6 x 1.0
Torque Value
7.5 ft-lbs (10 N·m)
Important Notes
Secures the transmission pan to the transmission case. Use a star pattern to evenly tighten. Estimated value.
4

Transmission Fill Plug

M22 x 1.5
Torque Value
25 ft-lbs (34 N·m)
Important Notes
Secures the transmission fill plug. Prevents fluid leakage. Estimated value.
5

Transmission Drain Plug

M18 x 1.5
Torque Value
25 ft-lbs (34 N·m)
Important Notes
Secures the transmission drain plug. Prevents fluid leakage. Estimated value.
6

Transmission Fluid Cooler Line Fittings (Transmission Side)

M16 x 1.5
Torque Value
20 ft-lbs (27 N·m)
Important Notes
Secures the transmission fluid cooler lines to the transmission. Proper torque ensures a leak-free seal. Estimated value.
7

Torque Converter Bolts (Flywheel/Flexplate)

M10 x 1.5
Torque Value
37 ft-lbs (50 N·m)
Important Notes
Secures the torque converter to the flywheel/flexplate. Use a star pattern to evenly tighten. Estimated value.

Driveshaft Axles

Torque specifications for components related to the driveshaft and axles, ensuring proper power transfer to the wheels.

1

Driveshaft Center Support Bearing Bolts (if applicable)

M10 x 1.5
Torque Value
35 ft-lbs (47 N·m)
Important Notes
Secures the driveshaft center support bearing. Estimated value.
2

Front Axle Nut (Hub)

M24 x 1.5
Torque Value
155 ft-lbs (210 N·m)
Important Notes
Secures the front axle to the wheel hub. Always replace this nut after removal. Estimated value.
3

Rear Axle Nut (Hub)

M24 x 1.5
Torque Value
155 ft-lbs (210 N·m)
Important Notes
Secures the rear axle to the wheel hub. Always replace this nut after removal. Estimated value.
4

Axle CV Joint Bolts (Transmission Side)

M10 x 1.5
Torque Value
35 ft-lbs (47 N·m)
Important Notes
Fastens the CV joint to the transaxle flange. Use a star pattern to evenly tighten. Estimated value.
5

Axle CV Joint Bolts (Wheel Hub Side)

M10 x 1.5
Torque Value
35 ft-lbs (47 N·m)
Important Notes
Fastens the CV joint to the wheel hub. Use a star pattern to evenly tighten. Estimated value.

Differential

Torque specifications for components related to the differential, ensuring secure mounting and proper sealing for fluid retention.

1

Differential Mounting Bolts

M14 x 2.0
Torque Value
70 ft-lbs (95 N·m)
Important Notes
Secures the differential to the chassis or subframe. Estimated value.
2

Differential Housing Bolts (Cover Bolts)

M10 x 1.5
Torque Value
25 ft-lbs (34 N·m)
Important Notes
Secures the differential cover. Use a star pattern to evenly tighten. Estimated value.
3

Differential Fill Plug

M20 x 1.5
Torque Value
25 ft-lbs (34 N·m)
Important Notes
Secures the differential fill plug. Prevents fluid leakage. Estimated value.
4

Differential Drain Plug

M20 x 1.5
Torque Value
25 ft-lbs (34 N·m)
Important Notes
Secures the differential drain plug. Prevents fluid leakage. Estimated value.

Transfer Case

Torque specifications for components related to the transfer case, ensuring secure mounting and proper sealing for fluid retention.

1

Transfer Case Mounting Bolts

M12 x 1.75
Torque Value
60 ft-lbs (81 N·m)
Important Notes
Secures the transfer case to the transmission. Estimated value.
2

Transfer Case Fill Plug

M20 x 1.5
Torque Value
20 ft-lbs (27 N·m)
Important Notes
Secures the transfer case fill plug. Prevents fluid leakage. Estimated value.
3

Transfer Case Drain Plug

M20 x 1.5
Torque Value
20 ft-lbs (27 N·m)
Important Notes
Secures the transfer case drain plug. Prevents fluid leakage. Estimated value.

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 torque specifications so important for drivetrain bolts?

Proper torque ensures bolts are tightened enough to hold components securely without being overstressed. Under-tightening can cause components to loosen during operation, leading to vibrations, noises, and potential failure. Over-tightening can stretch or break bolts, causing just as much damage, and/or stripping threads on your vehicle's transmission or differential case. Using a torque wrench and following the prescribed torque specification is crucial for safety and reliability.

Q2

What happens if I don't have a torque wrench?

While you can attempt to tighten bolts 'by feel,' it's not recommended for critical components like drivetrain bolts. A torque wrench allows you to apply a precise amount of force. If you don't have one, borrowing or purchasing one is wise. Not using one can result in damage, and is not a risk worth taking, especially given the nature of a drivetrain. The repair will almost certainly cost more than a wrench.

Q3

Can I reuse drivetrain bolts?

Some bolts, particularly those that stretch when tightened (Torque-to-Yield or TTY bolts), are designed for one-time use and should always be replaced. Others might be reusable, but it's good practice to inspect them for damage, and replace if you are at all in doubt. Refer to the vehicle's service manual for bolt reuse recommendations. Generally, any bolt with a lock feature (such as a nylon patch or threadlocker) will need replacement after removal.

Q4

How do I know if a bolt is a torque-to-yield bolt?

Torque-to-yield bolts are typically identified in the vehicle's service manual. They often have a torque specification that includes a degree of rotation after an initial torque value (for example 30 Nm + 90 degrees). Consult your manual to be sure and never attempt to reuse a torque to yield bolt. Ignoring this could lead to sudden failure, resulting in an expensive repair and/or injury.

Q5

Do I need to use thread locker?

Thread locker should be used according to the vehicle manufacturer's specification. If a service manual recommends thread locker, do not omit this step. In many cases, certain areas of the drivetrain may experience extreme temperatures, or vibrations that require extra hold on bolts. Omitting the thread locker could lead to vibrations and bolt loosening, which would be very dangerous.

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-inch Drive)

A calibrated torque wrench capable of accurately measuring torque in the specified ranges for drivetrain components.

  • Click-type or digital readout
  • Wide torque range (e.g., 20-150 ft-lbs)
Learn more

Torque Wrench (3/8-inch Drive)

A calibrated torque wrench capable of accurately measuring torque in the specified ranges for smaller drivetrain components.

  • Click-type or digital readout
  • Torque range suitable for smaller fasteners (e.g., 5-80 ft-lbs)
Learn more

Socket Set (Metric)

A comprehensive set of metric sockets, both standard and deep well, in various sizes to fit drivetrain bolts and nuts.

  • Sizes ranging from 10mm to 24mm
  • 6-point and 12-point sockets
Learn more

Extension Bars (Various Lengths)

Extension bars in various lengths to reach difficult-to-access drivetrain fasteners.

  • 1/2-inch and 3/8-inch drive options
  • Different lengths for flexibility
Learn more

Universal Joint

A universal joint adapter to access drivetrain fasteners at an angle.

  • 1/2-inch and 3/8-inch drive options
  • Durable construction
Learn more
Service Procedures

Driveshaft Bolt Torque Procedure

This procedure outlines the steps for properly torquing the driveshaft bolts on a Buick Regal.

  • 1. Locate the driveshaft bolts.
  • 2. Clean the threads of the bolts and mating surfaces.
  • 3. Install the bolts finger tight.
  • 4. Using a torque wrench, torque the bolts to the specified torque (typically 65 ft-lbs) using a star pattern for even clamping.
  • 5. Verify all bolts are torqued to specification.
  • 6. Perform a visual inspection of bolt and driveline connection.
View full procedure

Axle Shaft Nut Torque Procedure

This procedure outlines the steps for properly torquing the axle shaft nuts on a Buick Regal.

  • 1. Locate the axle shaft nuts.
  • 2. Clean the threads of the nuts and mating surfaces.
  • 3. Install the nuts finger tight.
  • 4. Using a torque wrench, torque the nuts to the specified torque (typically 155 ft-lbs) and specified angle rotation (typically 50-60 degrees) if necessary.
  • 5. Verify all nuts are torqued and rotated to specification.
  • 6. Perform a visual inspection of nut and axle connection.
View full procedure

Transmission Mount Bolt Torque Procedure

This procedure outlines the steps for properly torquing the transmission mount bolts on a Buick Regal.

  • 1. Locate the transmission mount bolts.
  • 2. Clean the threads of the bolts and mating surfaces.
  • 3. Install the bolts finger tight.
  • 4. Using a torque wrench, torque the bolts to the specified torque (typically 40-60 ft-lbs) based on the specific mount location.
  • 5. Verify all bolts are torqued to specification.
  • 6. Perform a visual inspection of mount and bolt connection.
View full procedure
Technical Service Bulletins

Driveline Vibration After Repair

2020-05-15

Some 2018-2020 Buick Regal models may experience driveline vibrations after driveline component replacement. This is sometimes due to improper torque specification on bolts or a driveshaft or axle phasing issue.

2018-2020

Resolution: Ensure all driveline bolts are torqued to the correct specification. Verify driveshaft and axle phasing is correct. If the issue persists inspect for other driveline related issues such as u-joint or CV joint problems.

Rear Axle Shaft Nut Loosening

2021-11-01

Certain 2019-2021 Buick Regal models may experience loosening of the rear axle shaft nuts. This can result in unusual noises and driveline issues.

2019-2021

Resolution: Inspect and ensure axle shaft nuts are torqued to specification and angle rotation. Replace any nuts found loose or damaged. Apply threadlocker compound during reassembly for added security. Perform a test drive and verify the issue is resolved.

Transmission Mount Bolt Loosening

2022-03-10

Some 2018-2022 Buick Regal models have experienced transmission mount bolt loosening. Check for signs of mount wear or deformation.

2018-2022

Resolution: Inspect all transmission mount bolts. Replace any bolts that show signs of damage. Torque bolts to specification. Apply thread locker to all bolts and re-check after 500-1000 miles for loosening.

About the Author

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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.

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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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