Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

1989 GMC Forward Control 5.7 K, Automatic, 3L80/M40FACTORY OEM SERVICE PROCEDURE

Torque Specifications: V8

TORQUE SPECIFICATIONS (V8)

Application	Ft. Lbs. (N.m)
Bellhousing-to-Engine	30 (41)
Front Mount-to-Chassis	35 (47)
Front Mount-to-Engine	36 (49)
Front Mount Through Bolt	85 (115)
Flex Plate-to-Converter	35 (47)
Rear Mount-to-Crossmember	36 (49)
Rear Mount-to-Transmission	36 (49)

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.

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