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 Ford Probe GL, AutomaticFACTORY OEM SERVICE PROCEDURE
Speedometer Calibration Check
- Drive vehicle on road with measured mile markers at 30 MPH and 60 MPH. Time intervals between markers. Divide 60 by number of minutes between mile markers to calculate actual vehicle speed.
- Compare actual vehicle speeds with specifications. See the SPEEDOMETER SPECIFICATIONS
table. If actual speeds are within specifications, speedometer is working properly.NOTE: Improper tire size will cause error in readings.
- Remove speedometer cable if readings are not within specifications, if readings fluctuate or if there are no readings. If cable is okay, replace speedometer.
SPEEDOMETER SPECIFICATIONS
| Standard Indication (MPH) | Allowable Range (MPH) |
|---|---|
| 30 | 27.0-34.5 |
| 60 | 54-69 |
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.