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
Riding Height Specifications
RIDING HEIGHT SPECIFICATIONS
| Application | (mm) | |||
|---|---|---|---|---|
| C/K Series | ||||
| "Z" Heights | 73.6 +/- 6.0 | |||
| "D" Heights | 182 +/- 6.0 | |||
| R/V & G/P (10-30 Series) | (1) | |||
| S/T Series | ||||
| "Z" Heights (S Series) | 73.0 +/- 6.0 | |||
| "Z" Heights (T Series) | 122.0 +/- 6.0 | |||
| "D" Heights | 170/0 +/- 6.0 | |||
| Astro/Safari | ||||
| "Z" Heights | 80.0 +/- 6.0 | |||
| "D" Heights (1988) | 150.0 +/- 15 | |||
| "D" Heights (1989) | 135.0 +/- 6.0 | |||
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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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