Diagnosis and Testing - Preliminary Inspection

Overview

The preliminary inspection is part of the automatic transmission diagnosis. The preliminary inspection is used to identify obvious causes of transmission concerns.

To correctly diagnose the concern, first understand the customer's concern or condition. Contact with the customer may be required to understand the conditions, including when the concern occurs.

Under-Hood Inspection

1. 1
   Check for missing or damaged air intake components.
2. 2
   Inspect the wiring harness for correct routing, especially near the rear of the cylinder heads. Make sure the harness is not chafed or pinched.
3. 3
   Inspect the transmission fluid cooler for correct installation and check for missing air deflectors.

Underbody Inspection

1. 1
   Position the vehicle on the lift in NEUTRAL.
   REFER TO: Lifting and Jacking - Overview (100-02 Jacking and Lifting, Description and Operation).
2. 2
   Move the selector lever to the D position.
3. 3
   Inspect the transmission case for leaks.
4. 4
   Inspect the transmission fluid cooler lines for correct routing, pinches or kinks.
5. 5
   Inspect the transmission fluid cooler mounting and check for missing air deflectors.
6. 6
   Adjust the selector lever cable (if equipped).

Transmission Fluid Check

Transmission Fluid Condition can provide many clues to the nature of a transmission concern. The correct transmission fluid level can only be determined with the transmission fluid within the specified temperature range. It is not necessary to check the exact transmission fluid level at this time. If the transmission fluid temperature is below operating temperature, a low level is expected on the transmission fluid level indicator. Transmission fluid temperature below 30.2 °F (-1 °C) may not show on the transmission fluid level indicator.

1. 1
   Position the vehicle on the lift in NEUTRAL.
   REFER TO: Lifting and Jacking - Overview (100-02 Jacking and Lifting, Description and Operation).
2. 2
   Remove the transmission fluid filler plug or the transmission fluid level indicator.
3. 3
   Place a drop of transmission fluid on a facial tissue or white sheet of paper.
4. 4
   Inspect the stain. Under normal conditions the fluid color will darken and an odor may be present. Color and odor should not be used to determine the condition of the fluid or transmission.
   

   • Trace amounts of black or shiny metallic particles may be present as a result of normal wear and operation. The presence of a few particles in the sample does not necessarily indicate a transmission concern.

   • Large amounts of black particles usually represent burnt friction material.

   • A large quantity of fine and medium shiny metallic particles may indicate excessive wear of hard components.

   • A foamy pink color indicates water or engine coolant has entered the transmission.

Water in Transmission Fluid

To correctly repair an automatic transmission that has had water or engine coolant introduced into the system, completely disassemble, clean and replace the following components:

• All internal and external seals
• All friction materials
• Torque converter
• All components with bonded seals
• All solenoids
• All transmission fluid filters

Prior to transmission installation, flush and clean the transmission fluid cooler(s) and the transmission fluid cooler lines and hoses.