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: V6
TORQUE SPECIFICATIONS (V6)
| Application | Ft. Lbs. (N.m) | |
|---|---|---|
| 2.8L | ||
| Bellhousing-to-Engine | 75 (102) | |
| Front Mount-to-Chassis | 30-41 (41-56) | |
| Front Mount-to-Engine Bracket | 35 (47) | |
| Flex Plate-to-Converter | 35 (47) | |
| Rear Mount-to-Crossmember | 23 (31) | |
| Rear Mount-to-Transmission | 42 (57) | |
| 4.3L | ||
| Bellhousing-to-Engine | 35 (47) | |
| Front Mount Through Bolt | 72 (98) | |
| Front Mount-to-Chassis | 35 (47) | |
| Front Mount-to-Engine Bracket | 36 (49) | |
| Flex Plate-to-Converter | 35 (47) | |
| Rear Mount-to-Crossmember | 36 (49) | |
| Rear Mount-to-Transmission | 38 (51) | |
Factory Service Tools
Use the Manual With the Right Hardware
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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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