Diagnosing Notchy Shifting After Transmission Fluid Change in G37 Cars

The Infiniti G37 is a popular sports sedan known for its powerful engine and responsive handling․ However, some owners have reported experiencing notchy shifting issues after a transmission fluid change․ This article will guide you through the common causes of this problem and provide troubleshooting tips to help you diagnose and address the issue․

Understanding Notchy Shifting

Notchy shifting, also known as harsh shifting, is characterized by a noticeable clunk or jerk when the transmission shifts gears․ This can be uncomfortable for the driver and can also indicate potential problems with the transmission․

Potential Causes of Notchy Shifting After Transmission Fluid Change

Here are some common reasons why a G37 might experience notchy shifting after a transmission fluid change⁚

• Incorrect Transmission Fluid⁚ Using the wrong type of transmission fluid can affect the fluid’s viscosity and lubrication properties, leading to notchy shifting․
• Contaminated Fluid⁚ If the transmission fluid was contaminated during the change, it could introduce debris into the system, causing wear and tear on the transmission components․
• Air in the Transmission⁚ Air bubbles in the transmission fluid can interfere with proper hydraulic pressure, resulting in notchy shifting․
• Improper Fluid Level⁚ An incorrect fluid level can cause the transmission to operate outside its optimal range, leading to shifting problems․
• Transmission Filter Issues⁚ A clogged or worn transmission filter can restrict fluid flow and cause shifting issues․
• Transmission Solenoid Problems⁚ Transmission solenoids control fluid flow to the clutches and brakes within the transmission․ A faulty solenoid can cause shifting problems․
• Transmission Control Module (TCM) Issues⁚ The TCM controls the transmission’s operation․ A faulty TCM can lead to incorrect shifting patterns and notchy shifting․

Troubleshooting and Diagnosis

Here are some steps to diagnose the cause of notchy shifting after a transmission fluid change⁚

1. Verify Fluid Type⁚ Double-check that the correct type of transmission fluid was used․ Refer to your owner’s manual or consult a qualified mechanic․
2. Inspect Fluid Level⁚ Ensure the transmission fluid level is within the recommended range․ Check the fluid level when the engine is running and at operating temperature․
3. Check for Contamination⁚ Inspect the transmission fluid for any signs of contamination, such as debris or discoloration․ If the fluid is contaminated, it may need to be flushed and replaced․
4. Inspect the Transmission Filter⁚ If the transmission filter is accessible, inspect it for signs of wear or clogging․ Replace the filter if necessary․
5. Scan for Diagnostic Trouble Codes (DTCs)⁚ Use an OBD-II scanner to check for any DTCs related to the transmission․ These codes can provide valuable insights into the problem․
6. Consult a Mechanic⁚ If the issue persists, consult a qualified mechanic for further diagnosis and repair․

Preventing Future Problems

To prevent notchy shifting problems after a transmission fluid change, follow these recommendations⁚

• Use the correct type of transmission fluid specified by the manufacturer․
• Ensure the fluid is clean and free of contaminants․
• Maintain the proper fluid level․
• Replace the transmission filter at recommended intervals․

By following these steps, you can diagnose and address notchy shifting problems after a transmission fluid change in your G37 and restore smooth shifting performance․