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.

1991 Mercury Cougar LS, 3.8 4FACTORY OEM SERVICE PROCEDURE

Drive Belt Adjustment Specifications

BELT ADJUSTMENT ⁽¹⁾

Application

New Belt

Used Belt

4.6L

110-130 (48-57)

100-120 (44-53)

5.0L HO (6-Rib)

100-130 (44-57)

90-120 (40-53)

5.0L Except HO ⁽²⁾

100 (44)

90 (40)

⁽¹⁾	Tension In Lbs. (kg) Using Standard Belt Tension Gauge.

⁽²⁾	Specification is for reference only, belt is non-adjustable.

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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