Symptom Related Diagnostic Procedures

DIAGNOSIS
Before diagnosis of any transmission complaint is attempted, there must be understanding of fluid checking procedure and what appearance the fluid should have. Many times a transmission malfunction can be traced to low fluid level or improper reading of oil level gauge. Due to the transmission fluid that is now being used it may appear to be darker and have a stronger odor.

This is normal, and not a positive sign of required maintenance or transmission failure. Also when the oil level gauge is removed, it should be noted whether the fluid is devoid of air bubbles or not. Fluid with air bubbles gives an indication of an air leak in the suction lines, which can cause erratic operation and slippage. Water in the fluid imparts a milky, pink cast to the fluid and can cause spewing. Water in the fluid can also cause swelling of nylon parts.

PRELIMINARY CHECKING PROCEDURE
1. Check and correct fluid level.
2. Road test vehicle to verify transmission problem using all selective ranges, noting discrepancies in operation.
3. If engine performance indicates an engine tune-up is required, this should be performed before road testing is completed or transmission correction attempted. Poor engine performance can result in transmission problems.
4. Check kick-down cable adjustment.
5. Check and correct vacuum lines and fittings.
6. Check and correct select cable.
7. Install oil pressure gauge and compare with pressure readings.
8. Isolate the unit or circuit involved in the malfunction.