GMC Vehicle Models Safari 1985-1994 Torque Specifications
GMC Vehicle Models Safari 1985-1994

GMC Vehicle Models Safari 1985-1994 Torque Specifications

Complete GMC Vehicle Models Safari 1985-1994 torque specifications guide. Includes factory-specified torque values, torque sequences, and technical specifications for all components including body, brakes, drivetrain, electrical, emissions sensors, fuel, exhaust, HVAC, and suspension. Essential information for proper assembly and maintenance.

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

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Search by component name, bolt size, or description

Torque Calculator

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Body

Torque specifications for Body

Fuel System

1

Fuel Tank Strap Bolts

M8 x 1.25
Torque Specification
26 ft-lbs (35 N·m)
Important Notes
Ensure the fuel tank is properly aligned before tightening.
2

Fuel Filler Neck Bolts

M6 x 1.0
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Ensure the filler neck gasket is properly seated to prevent leaks.

Electrical System

1

Battery Terminal Nuts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Ensure the terminals are clean and free of corrosion before tightening.

Suspension And Steering

1

Strut/Shock Absorber Mounting Bolts

M12 x 1.5
Torque Specification
70 ft-lbs (95 N·m)
Important Notes
Follow the manufacturer's recommended torque sequence for proper alignment.
2

Control Arm Bolts

M12 x 1.5
Torque Specification
70 ft-lbs (95 N·m)
Important Notes
Ensure the control arm is properly aligned before tightening.
3

Sway Bar Link Nut

M10 x 1.25
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Ensure the sway bar link is properly aligned before tightening.
4

Steering Gear/Rack Bolts

M14 x 1.5
Torque Specification
90 ft-lbs (122 N·m)
Important Notes
Follow the manufacturer's recommended torque sequence for proper alignment.

Wheels And Tires

1

Wheel Lug Nuts

M12 x 1.5
Torque Specification
100 ft-lbs (135 N·m)
Important Notes
Use a star pattern to ensure even tightening and prevent warping of the wheel.

Body Panels And Accessories

1

Body Panel Bolts (e.g., fender, door hinges, hood hinges)

M6 x 1.0
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.
2

Bumper Mounting Bolts

M8 x 1.25
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.
3

Seat Belt Anchor Bolts

M10 x 1.25
Torque Specification
40 ft-lbs (54 N·m)
Important Notes
Critical for safety. Ensure proper alignment before tightening.
4

Roof Rack Mounting Bolts

M6 x 1.0
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.
5

Tailgate Hinge Bolts

M6 x 1.0
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.
6

Mirror Mounting Bolts

M5 x 0.8
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.
7

Door Handle Bolts

M5 x 0.8
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.
8

Grille Mounting Bolts

M6 x 1.0
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.

Brakes

Torque specifications for Brakes

Brake Caliper

1

Brake Caliper Bolts

M10 x 1.25
Torque Specification
40 ft-lbs (54 N·m)
Important Notes
Ensure the caliper is properly aligned before torquing.
2

Brake Caliper Mounting Bracket Bolts

M12 x 1.5
Torque Specification
80 ft-lbs (108 N·m)
Important Notes
Ensure the bracket is securely attached to the steering knuckle or axle.

Brake Rotor Drum

1

Brake Disc/Drum Retaining Bolts

M8 x 1.25
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Ensure the rotor or drum is properly seated on the hub before torquing.

Wheel Attachment

1

Wheel Lug Nuts

M12 x 1.5
Torque Specification
100 ft-lbs (135 N·m)
Important Notes
Always torque lug nuts in a star pattern to ensure even pressure.

Brake Hydraulics

1

Brake Hose Banjo Bolt

M10 x 1.0
Torque Specification
25 ft-lbs (34 N·m)
Important Notes
Ensure the sealing washers are properly seated before torquing.
2

Brake Master Cylinder Mounting Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Ensure the master cylinder is properly aligned with the brake booster.
3

Brake Booster Mounting Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Ensure the booster is properly aligned with the firewall.
4

Brake Line Fittings

M10 x 1.0
Torque Specification
12 ft-lbs (16 N·m)
Important Notes
Ensure the fittings are properly seated before torquing.

Drivetrain

Torque specifications for Drivetrain

Engine Transmission Interface

1

Flywheel Bolts

M10 x 1.25
Torque Specification
60 ft-lbs (81 N·m)
Important Notes
Ensure the flywheel is properly aligned before tightening.
2

Transmission Bellhousing Bolts

M8 x 1.25
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Ensure proper alignment of the transmission to the engine.

Transmission Assembly

1

Transmission Mounting Bolts

M10 x 1.5
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Ensure the transmission is properly aligned with the frame.
2

Transmission Oil Pan Bolts

M6 x 1.0
Torque Specification
6.7 ft-lbs (9 N·m)
Important Notes
Use a new gasket and ensure the pan is clean before installation.
3

Transmission Drain and Fill Plugs

M12 x 1.5
Torque Specification
20 ft-lbs (27 N·m)
Important Notes
Ensure the threads are clean and free of debris.

Driveshaft Assembly

1

Propeller/Drive Shaft Bolts

M8 x 1.25
Torque Specification
14 ft-lbs (19 N·m)
Important Notes
Ensure the driveshaft is properly balanced before tightening.
2

Transfer Case Output Shaft Flange Bolts

M10 x 1.5
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Ensure the flange is properly aligned with the driveshaft.

Differential Assembly

1

Differential Cover Bolts

M8 x 1.25
Torque Specification
20 ft-lbs (27 N·m)
Important Notes
Use a new gasket and ensure the cover is clean before installation.
2

Differential Drain/Fill Plug

M12 x 1.5
Torque Specification
25 ft-lbs (34 N·m)
Important Notes
Ensure the threads are clean and free of debris.
3

Differential Pinion Flange Nut

M20 x 1.5
Torque Specification
200 ft-lbs (271 N·m)
Important Notes
Ensure the pinion gear is properly aligned before tightening.

Transfer Case Assembly

1

Transfer Case Mounting Bolts

M10 x 1.5
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Ensure the transfer case is properly aligned with the frame.
2

Transfer Case Drain/Fill Plug

M12 x 1.5
Torque Specification
25 ft-lbs (34 N·m)
Important Notes
Ensure the threads are clean and free of debris.

Axle And Cv Joints

1

Drive Axle/Half Shaft Bolts

M10 x 1.5
Torque Specification
60 ft-lbs (81 N·m)
Important Notes
Ensure the axle is properly seated before tightening.
2

CV Joint/Axle Nut

M24 x 1.5
Torque Specification
180 ft-lbs (244 N·m)
Important Notes
Ensure the CV joint is properly seated before tightening.

Electrical

Torque specifications for Electrical

Ignition System

1

Ignition Coil Bolt

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Ensure the ignition coil is properly seated before tightening.

Starting System

1

Starter Motor Mounting Bolts

M10 x 1.5
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Ensure the starter motor is properly aligned with the flywheel.

Charging System

1

Alternator Mounting Bolts

M10 x 1.5
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Ensure the alternator belt is properly tensioned after installation.

Battery System

1

Battery Terminal Nuts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Ensure the terminals are clean and free of corrosion before tightening.

A C System

1

A/C Compressor Mounting Bolts

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Ensure the compressor is properly aligned with the belt.
2

A/C Line Fittings

M8 x 1.25
Torque Specification
12 ft-lbs (16 N·m)
Important Notes
Ensure the O-rings are properly seated before tightening.

Grounding System

1

Ground Strap Bolts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Ensure the grounding points are clean and free of corrosion.

Fuse And Relay System

1

Fuse Box Mounting Bolts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Ensure the fuse box is properly aligned before tightening.

Wiring Harness System

1

Wiring Harness Clamp Bolts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Ensure the wiring harness is properly routed before tightening.

Sensor System

1

Sensor Mounting Bolts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Ensure the sensor is properly aligned before tightening.

Lighting System

1

Headlight Mounting Bolts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Ensure the headlight is properly aligned before tightening.

Emissions Sensors

Torque specifications for Emissions_sensors

Egr System

1

EGR Valve Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Ensure the EGR valve is properly aligned before tightening.

Exhaust Manifold

1

Exhaust Manifold/Headers Bolts

M10 x 1.5
Torque Specification
26 ft-lbs (35 N·m)
Important Notes
Follow the manufacturer's recommended torque sequence to avoid warping the manifold.
2

Exhaust Manifold/Headers to Cylinder Head Bolts

M8 x 1.25
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Ensure the manifold is properly aligned before tightening.
3

Exhaust Pipe to Exhaust Manifold/Headers Bolts

M10 x 1.5
Torque Specification
26 ft-lbs (35 N·m)
Important Notes
Ensure the exhaust pipe is properly aligned before tightening.

Catalytic Converter

1

Catalytic Converter to Exhaust Pipe Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Ensure the catalytic converter is properly aligned before tightening.

Intake System

1

Throttle Body Bolts

M6 x 1.0
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Ensure the throttle body is properly aligned before tightening.
2

Intake Manifold Bolts

M8 x 1.25
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Follow the manufacturer's recommended torque sequence to avoid warping the manifold.

Emissions Sensors

1

Oxygen Sensor (O2 Sensor) Mounting Nut

M12 x 1.5
Torque Specification
30 ft-lbs (41 N·m)
Important Notes
Ensure the sensor is properly aligned before tightening. Over-tightening can damage the sensor.
2

MAP Sensor Mounting Bolts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Ensure the sensor is properly aligned before tightening.
3

MAF Sensor Mounting Bolts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Ensure the sensor is properly aligned before tightening.
4

PCV Valve Mounting Bolt

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Ensure the valve is properly aligned before tightening.
5

Evaporative Emissions Canister Mounting Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Ensure the canister is properly aligned before tightening.

Exhaust

Torque specifications for Exhaust

Exhaust Manifold Headers

1

Exhaust Manifold/Headers to Cylinder Head Bolts

M10 x 1.25
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Ensure bolts are tightened in a crisscross pattern to evenly distribute pressure.
2

Exhaust Pipe to Exhaust Manifold/Headers Bolts

M10 x 1.25
Torque Specification
26 ft-lbs (35 N·m)
Important Notes
Ensure gasket is properly seated before tightening.

Catalytic Converter

1

Catalytic Converter to Exhaust Pipe Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Use a new gasket to ensure a proper seal.

Muffler

1

Muffler to Exhaust Pipe Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Ensure gasket is properly seated before tightening.

Exhaust Hangers

1

Exhaust Hanger Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Estimated value based on similar components.

Oxygen Sensor

1

Oxygen Sensor (O2 Sensor) Bolts

M12 x 1.5
Torque Specification
30 ft-lbs (41 N·m)
Important Notes
Ensure the sensor is properly aligned before tightening.

Exhaust Flanges

1

Exhaust Flange Bolts (Mid-Pipe to Catalytic Converter or Muffler)

M10 x 1.25
Torque Specification
26 ft-lbs (35 N·m)
Important Notes
Ensure gasket is properly seated before tightening.

Heat Shields

1

Heat Shield Bolts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Estimated value based on similar components.

Fuel

Torque specifications for Fuel

Fuel Rail System

1

Fuel Rail Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Ensure bolts are tightened in a crisscross pattern to evenly distribute pressure.
2

Fuel Injector Bolts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Over-tightening can damage the injector seals.

Fuel Delivery System

1

Fuel Pump Mounting Bolts

M10 x 1.5
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Ensure the fuel pump is properly aligned before tightening.
2

Fuel Tank Strap Bolts

M12 x 1.75
Torque Specification
26 ft-lbs (35 N·m)
Important Notes
Ensure the fuel tank is properly supported before tightening.
3

Fuel Filler Neck Bolts

M8 x 1.25
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Ensure a proper seal to prevent fuel vapor leaks.

Fuel Filtration System

1

Fuel Filter Bolt/Nut

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Ensure the fuel filter is properly aligned before tightening.

Fuel Pressure Regulation

1

Fuel Pressure Regulator Bolts

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Over-tightening can damage the regulator seals.

Fuel Tank Sensor System

1

Fuel Tank Sender Unit Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Ensure a proper seal to prevent fuel leaks.

Hvac

Torque specifications for Hvac

Ac Compressor

1

A/C Compressor Mounting Bolts

M10 x 1.25
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Ensure bolts are tightened in a crisscross pattern to evenly distribute load.

Ac Lines

1

A/C Line Fittings

M8 x 1.0
Torque Specification
12 ft-lbs (16 N·m)
Important Notes
Use a torque wrench to avoid overtightening, which can damage O-rings.

Evaporator Housing

1

Evaporator Housing Bolts

M6 x 1.0
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Estimated value based on similar M6 bolts in HVAC systems.

Blower Motor

1

Blower Motor Mounting Bolts

M5 x 0.8
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Estimated value based on similar M5 bolts in HVAC systems.

Heater Core

1

Heater Core Inlet/Outlet Fittings

M8 x 1.0
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Estimated value based on similar M8 fittings in HVAC systems.

Control Panel

1

HVAC Control Panel Mounting Screws

M4 x 0.7
Torque Specification
0.67 ft-lbs (0.9 N·m)
Important Notes
Estimated value based on similar M4 screws in HVAC systems.

Suspension

Torque specifications for Suspension

Strut Shock Absorber

1

Strut/Shock Absorber Mounting Bolts

M12 x 1.5
Torque Specification
70 ft-lbs (95 N·m)
Important Notes
Ensure bolts are tightened evenly to avoid misalignment.
2

Upper Strut Mount Bolts

M10 x 1.25
Torque Specification
50 ft-lbs (68 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.
3

Lower Shock Absorber Mounting Bolts

M10 x 1.25
Torque Specification
55 ft-lbs (75 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.

Control Arm Ball Joint

1

Control Arm Bolts

M12 x 1.5
Torque Specification
70 ft-lbs (95 N·m)
Important Notes
Ensure bolts are tightened evenly to avoid misalignment.
2

Ball Joint Nut

M12 x 1.25
Torque Specification
65 ft-lbs (88 N·m)
Important Notes
Ensure the ball joint is properly seated before tightening.

Steering System

1

Tie Rod End Nut

M10 x 1.25
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Ensure the tie rod end is properly seated before tightening.
2

Steering Gear/Rack Bolts

M14 x 1.5
Torque Specification
1. 45 ft-lbs (61 N·m) 2. 90°
Important Notes
Follow the torque sequence to ensure even clamping force.
3

Steering Knuckle Bolts

M12 x 1.5
Torque Specification
80 ft-lbs (108 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.

Sway Bar

1

Sway Bar Link Nut

M10 x 1.25
Torque Specification
35 ft-lbs (47 N·m)
Important Notes
Ensure the sway bar link is properly seated before tightening.
2

Sway Bar Bracket Bolts

M8 x 1.25
Torque Specification
25 ft-lbs (34 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.

Wheel Hub

1

Wheel Lug Nuts

M12 x 1.5
Torque Specification
100 ft-lbs (135 N·m)
Important Notes
Always use a crisscross pattern when tightening wheel lug nuts.
2

Rear Axle U-Bolt Nuts

M14 x 1.5
Torque Specification
85 ft-lbs (115 N·m)
Important Notes
Estimated value based on similar components. Ensure proper alignment before tightening.

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

What IS the recommended torque specification for the lug nuts on a 1985-1994 GMC Safari?

Tighten the lug nuts to 95-110 ft-lbs (129-150 Nm) using a calibrated torque wrench in a star pattern.

Q2

What type of torque wrench IS recommended for tightening the engine head bolts on a GMC Safari?

Use a torque wrench with an adjustable range and a dial or digital display to ensure accurate torque application. Refer to the GMC service manual for specific head bolt torque specifications.

Q3

How should I torque the intake manifold bolts on my 1985-1994 GMC Safari?

Tighten the intake manifold bolts to 18-22 ft-lbs (24-30 Nm) following the specified tightening sequence. Use a torque wrench to avoid overtightening.

Q4

What IS the torque specification for the spark plugs on a 1985-1994 GMC Safari?

Install the spark plugs and tighten them to 7-15 ft-lbs (9-20 Nm) using a spark plug wrench or a torque wrench with an appropriate spark plug socket.

Q5

Can I use an impact wrench to tighten bolts on my GMC Safari?

While impact wrenches can be convenient, they can overtighten bolts and damage threads. Use a calibrated torque wrench for accurate torque application to avoid potential issues.

Q6

How often should I check the torque on critical bolts on my GMC Safari?

Inspect and retorque critical bolts, such as lug nuts, engine head bolts, and suspension bolts, according to the GMC service schedule or as needed after major repairs or modifications.

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

Digital Torque Wrench (10-100 Nm)

Essential for tightening fasteners to precise torque specifications, preventing damage and ensuring proper assembly. This range IS suitable for many applications on the Safari.

  • Digital display for accurate readings
  • Audible alarm when target torque IS reached
  • Multiple units (Nm, ft-lb, in-lb)
  • Reversible ratcheting mechanism
Learn more
Service Procedures

Engine Bolt Torque Specifications

Comprehensive guide to tightening engine bolts on the GMC Safari.

  • Cylinder head bolts: 85-95 Nm
  • Intake manifold bolts: 25-33 Nm
  • Exhaust manifold bolts: 35-45 Nm
  • Oil pan bolts: 13-18 Nm
View full procedure

Suspension Bolt Torque Specifications

Detailed instructions for tightening suspension bolts.

  • Upper control arm bolts: 80-100 Nm
  • Lower control arm bolts: 105-125 Nm
  • Tie rod end bolts: 55-65 Nm
  • Strut bolts: 75-85 Nm
View full procedure

Brake Bolt Torque Specifications

Safety-critical procedure for tightening brake system bolts.

  • Caliper mounting bolts: 100-120 Nm
  • Rotor mounting bolts: 90-110 Nm
  • Master cylinder bolts: 20-25 Nm
  • Wheel lug nuts: 140-160 Nm
View full procedure
Technical Service Bulletins

TSB 89-99-21: Erratic Engine Idle

1989-07-01

Provides diagnostic and repair instructions for an issue causing erratic engine idle on certain Safari models.

1985-1989 Safari

Resolution: Tighten the intake manifold bolts to 25-33 Nm as per updated specifications.

TSB 93-32-22: Loose Tie Rod End Nuts

1993-06-15

Addresses a potential safety issue involving loose tie rod end nuts.

1990-1994 Safari

Resolution: Inspect and retorque tie rod end nuts to 55-65 Nm.

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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.
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  • If you're unsure about any procedure, consult a qualified professional mechanic.
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About the Author

Expert automotive knowledge and experience

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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