Transmission Related:
* Low Transmission Fluid: This is the first and easiest thing to check. Low fluid can cause poor shifting and ultimately transmission damage. Check the fluid level with the engine running and warm. If it's low, top it off with the correct type of ATF (Automatic Transmission Fluid) for your car. However, low fluid is usually accompanied by other symptoms like slipping or delayed engagement in other gears. If its significantly low, investigate the leak source.
* Dirty or Low-Quality Transmission Fluid: Old, dirty fluid can lead to poor shifting and eventually transmission failure. A fluid change and filter replacement is recommended.
* Worn-out Clutch Packs/Bands: Inside the automatic transmission are clutch packs and bands that engage and disengage to change gears. Wear and tear can cause them to slip or fail to engage properly. This is a more significant repair.
* Faulty Shift Solenoids: These are electrically controlled valves within the transmission that control the fluid flow to engage the correct gears. A faulty solenoid can prevent the shift from 2nd to 3rd. This requires diagnostic tools to test.
* Valve Body Problems: The valve body houses the shift solenoids and other components that regulate fluid flow. Internal wear or damage can cause shifting issues. This is a major repair often involving a rebuild or replacement.
* Transmission Governor: This component measures the vehicle's speed and signals the transmission to shift. A malfunctioning governor can prevent the proper upshift.
* Internal Transmission Damage: More severe issues like broken internal parts, worn gears, or a failing torque converter can prevent the shift. This is often the most expensive repair and might require a rebuild or replacement of the transmission.
Other Potential Causes (Less Likely, but worth considering):
* Throttle Position Sensor (TPS): A faulty TPS can provide inaccurate engine speed information to the transmission control module (TCM), affecting shifting.
* Transmission Control Module (TCM): The TCM controls the transmission's operation. A faulty TCM can lead to various shifting problems. This usually requires specialized diagnostics.
* Wiring Issues: Damaged or corroded wiring related to the transmission or its control system could interrupt signals.
Troubleshooting Steps:
1. Check the transmission fluid level and condition. This is the most important first step.
2. Listen for any unusual noises coming from the transmission. Whining, grinding, or clunking sounds indicate internal problems.
3. Have the transmission fluid and filter changed. This is a relatively inexpensive preventative measure and can solve minor shifting issues.
4. Use an OBD-II scanner (if equipped) to check for any transmission-related trouble codes. This can pinpoint potential issues. A 1995 model might not have a full OBD-II system, but it could still provide some information.
5. Take it to a mechanic specializing in transmissions. They have the tools and expertise to diagnose the problem accurately.
The fact that it only happens between 2nd and 3rd suggests a problem specific to that gear change, making internal transmission issues or a specific solenoid more likely than a general transmission fluid problem. However, start with the easy checks (fluid level and condition) before moving on to more complex diagnostics.
