Buick Envision 2016-2020 6T45 Transmission Torque Specifications
Detailed torque specifications for all bolts related to the 6T45 automatic transmission used in the 2016-2020 Buick Envision. Includes torque values for various transmission 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
Transmission Mounting
Bolts that secure the transmission assembly to the engine and/or chassis.
1 Transmission Mounting Bolts
M12 x 1.75
Transmission Mounting Bolts
M12 x 1.75Torque Value
Important Notes
Transmission Case
Bolts that secure the transmission case halves and side cover.
1 Transmission Case Bolts
M10 x 1.5
Transmission Case Bolts
M10 x 1.5Torque Value
Important Notes
2 Side Cover Bolt
M8 x 1.25
Side Cover Bolt
M8 x 1.25Torque Value
Important Notes
Transmission Pan
Bolts that secure the transmission oil pan to the transmission case.
1 Transmission Oil Pan Bolts
M6 x 1.0
Transmission Oil Pan Bolts
M6 x 1.0Torque Value
Important Notes
Fluid Service
Plugs used for servicing the transmission fluid.
1 Transmission Drain and Fill Plugs
M18 x 1.5
Transmission Drain and Fill Plugs
M18 x 1.5Torque Value
Important Notes
Driveline Connections
Bolts connecting the drive axles to the transmission output shafts.
1 Drive Axle/Half Shaft Bolts
M10 x 1.5
Drive Axle/Half Shaft Bolts
M10 x 1.5Torque Value
Important Notes
2 CV Joint/Axle Nut
M24 x 1.5
CV Joint/Axle Nut
M24 x 1.5Torque Value
Important Notes
Transmission Cooling
Bolts and fittings that secure the transmission cooler lines to the transmission case.
1 Transmission Cooler Line Fittings/Banjo Bolt
M12 x 1.5
Transmission Cooler Line Fittings/Banjo Bolt
M12 x 1.5Torque Value
Important Notes
External Components
Bolts for external transmission components such as sensors and the range selector.
1 Transmission Range Selector/Manual Shaft Detent Bolt
M6 x 1.0
Transmission Range Selector/Manual Shaft Detent Bolt
M6 x 1.0Torque Value
Important Notes
2 Output Speed Sensor Mounting Bolt
M6 x 1.0
Output Speed Sensor Mounting Bolt
M6 x 1.0Torque Value
Important Notes
3 Input Speed Sensor Mounting Bolt
M6 x 1.0
Input Speed Sensor Mounting Bolt
M6 x 1.0Torque Value
Important Notes
4 TCM (Transmission Control Module) Mounting Bolts
M6 x 1.0
TCM (Transmission Control Module) Mounting Bolts
M6 x 1.0Torque Value
Important Notes
Internal Components
Bolts securing internal components such as the valve body, shift solenoids, and park actuator.
1 Valve Body Mounting Bolts
M6 x 1.0
Valve Body Mounting Bolts
M6 x 1.0Torque Value
Important Notes
2 Shift Solenoid Retaining Bolts
M5 x 0.8
Shift Solenoid Retaining Bolts
M5 x 0.8Torque Value
Important Notes
3 Park Actuator Bolts
M6 x 1.0
Park Actuator Bolts
M6 x 1.0Torque 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 precise torque specifications important for the 6T45 transmission?
Why are precise torque specifications important for the 6T45 transmission?
Precise torque specifications are crucial for the 6T45 transmission to ensure proper clamping force, prevent leaks, and avoid component damage. Under-torquing can lead to loosening and leaks, while over-torquing can strip threads or distort parts. For example, improper torque on the transmission pan bolts could cause fluid leaks, leading to transmission failure.
Q2 What happens if I over-torque a transmission bolt?
What happens if I over-torque a transmission bolt?
Over-torquing a bolt can stretch or break the bolt itself, or damage the threads in the transmission housing or component being bolted. This can lead to costly repairs, such as needing to extract a broken bolt or replace the damaged component. For instance, over-torquing the valve body bolts might cause cracks or distortions, affecting transmission performance.
Q3 What type of lubricant, if any, should be used on transmission bolts?
What type of lubricant, if any, should be used on transmission bolts?
Unless specified otherwise in the service manual, generally clean, dry threads are used on transmission bolts. Applying lubricant may affect the clamping force achieved at a given torque, resulting in inaccuracies. Some bolts may have thread locker pre-applied, but this is component-specific. Always consult the service manual. For example, transmission pan bolts do not typically require lubricant but some case bolts may use thread locker.
Q4 Do I need a special tool to torque transmission bolts?
Do I need a special tool to torque transmission bolts?
Yes, you will need a calibrated torque wrench to accurately torque transmission bolts to specifications. Using a standard wrench and estimating torque is highly inaccurate and not recommended. A torque wrench ensures consistent clamping force on all fasteners. For example, the side cover bolts or the transmission oil pan bolts need to be tightened using a calibrated torque wrench.
Q5 Are torque specs for the 6T45 different for different models and years of the Buick Envision?
Are torque specs for the 6T45 different for different models and years of the Buick Envision?
While the 6T45 transmission is generally consistent, there might be minor variations in torque specifications across different model years or specific sub-models. Always refer to the specific service manual for your vehicle's exact year and VIN for the most accurate information. For example, while core 6T45 bolt torques are consistent, fasteners related to different mount brackets might have year-specific adjustments.
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 inch drive)
A calibrated torque wrench capable of measuring torque values from 10 Nm to 100 Nm (or 7.4 ft-lbs to 74 ft-lbs).
- Accurate torque measurement
- Click-type or digital readout
Torque Wrench (3/8 inch drive)
A calibrated torque wrench capable of measuring torque values from 5 Nm to 30 Nm (or 3.7 ft-lbs to 22 ft-lbs)
- Accurate torque measurement
- Click-type or digital readout
Socket Set (Metric)
A set of metric sockets, including sizes 8mm, 10mm, 13mm, 15mm, 16mm, and 18mm.
- Various sizes for different bolts
- 6-point design for secure grip
Extension Bars (various sizes)
A selection of extension bars in 3/8 and 1/2 inch drive, allowing access to recessed bolts.
- Extends reach to fasteners
- Provides clearance for tight spots
Universal Joint
A 3/8 and 1/2 inch drive universal joint adapter for torque wrench, for use in hard to reach places.
- Allows for angle torque application
- Helps to work around obstructions
Service Procedures
6T45 Transmission Pan Bolt Torque
Procedure for torquing the transmission pan bolts on a 6T45 transmission.
- Clean the transmission pan and case mating surfaces.
- Install the transmission pan with a new gasket.
- Install the transmission pan bolts finger tight.
- Torque the pan bolts to 10 Nm (89 lb-in) using a criss-cross pattern.
- Re-torque the pan bolts to 20 Nm (15 lb-ft) using the same criss-cross pattern.
6T45 Transmission Case Bolt Torque
Procedure for torquing the case bolts on a 6T45 transmission.
- Install the transmission case with a new gasket.
- Install the transmission case bolts finger tight.
- Torque the transmission case bolts to 25 Nm (18 lb-ft) using a criss-cross pattern.
- Re-torque the pan bolts to 35 Nm (26 lb-ft) using the same criss-cross pattern.
6T45 Transmission Fluid Pump Bolt Torque
Procedure for torquing the transmission fluid pump bolts on a 6T45 transmission.
- Install the fluid pump assembly with a new seal.
- Install the pump bolts finger tight.
- Torque the pump bolts to 15 Nm (11 lb-ft) using a criss-cross pattern.
6T45 Transmission Valve Body Bolt Torque
Procedure for torquing the transmission valve body bolts on a 6T45 transmission.
- Install the valve body assembly.
- Install the valve body bolts finger tight.
- Torque the valve body bolts to 10 Nm (89 lb-in) using a criss-cross pattern.
Technical Service Bulletins
PIP5299A: Possible Transmission Oil Leak From Pan
2016-03-21Some 2016-2017 models may experience transmission oil leaks from the pan due to improper bolt torque during assembly.
Resolution: Verify correct torque specification for the pan bolts. Clean surfaces and reinstall with new gasket if leak is present.
17-NA-231: Transmission Fluid Leak at Case Connector
2017-12-15Transmission fluid leaks may be observed at case connector seal. The torque value for the retaining bolts may be a factor.
Resolution: Inspect connector seal and replace if needed. Verify bolts are correctly torqued to 25 Nm initial and then 35 Nm on the second torque pass.
19-NA-255: Harsh Shifting and/or Erratic Transmission Operation
2019-08-01Harsh or erratic shifting can result from improper installation of valve body. Correct installation torque is critical for proper valve body function.
Resolution: Verify valve body bolts are torqued to specification. If the issue is persistent, further diagnostics may be required.
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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.