The 2018 Toyota Highlander, lauded for its reliability and family-friendly features, isn't immune to issues. While generally a dependable vehicle, some owners have reported encountering problems with its transmission. Understanding these potential issues can help you identify, address, and even prevent them, ensuring your Highlander continues to serve your family for years to come.

Uh Oh, Is My 2018 Highlander's Transmission Acting Up?

One of the most disheartening experiences for a car owner is when their vehicle starts behaving strangely. In the case of the 2018 Toyota Highlander, transmission problems can manifest in several ways. Recognizing these symptoms early on is crucial for preventing further damage and costly repairs. Some common signs include:

  • Rough Shifting: Feeling a jolt or hesitation when the transmission shifts gears. This can be especially noticeable during acceleration or deceleration.
  • Slipping Gears: The engine revs up, but the vehicle doesn't accelerate as expected, or the transmission seems to "slip" out of gear.
  • Delayed Engagement: A noticeable delay between shifting into drive or reverse and the vehicle actually moving.
  • Unusual Noises: Whining, clunking, or humming sounds coming from the transmission area, particularly when shifting.
  • Shaking or Vibrating: Feeling unusual vibrations, especially at certain speeds or during gear changes.
  • Check Engine Light: The dreaded check engine light illuminating on your dashboard. While it can indicate various issues, it's essential to have it checked, as it could be related to a transmission problem.

If you experience any of these symptoms, it's essential to take your Highlander to a trusted mechanic for a thorough inspection.

What's Causing These Transmission Troubles?

Several factors can contribute to transmission problems in the 2018 Toyota Highlander. While some are related to the vehicle's design or manufacturing, others are due to maintenance practices or driving habits. Here's a breakdown of the most common causes:

  • Low Transmission Fluid: This is a frequent culprit. Low fluid levels can lead to increased friction and heat, causing damage to the transmission components.
  • Dirty or Contaminated Transmission Fluid: Over time, transmission fluid can degrade and become contaminated with debris, reducing its ability to lubricate and cool the transmission effectively.
  • Valve Body Issues: The valve body controls the flow of transmission fluid to different parts of the transmission. Malfunctions in the valve body can lead to shifting problems.
  • Torque Converter Problems: The torque converter is responsible for transferring power from the engine to the transmission. Issues with the torque converter can cause slipping, stalling, or rough shifting.
  • Software Glitches: In some cases, transmission problems can be attributed to software glitches in the transmission control module (TCM).
  • Internal Component Wear: Over time, internal components such as gears, clutches, and bearings can wear down, leading to transmission problems.
  • Overheating: Excessive heat can damage transmission components and accelerate wear. Towing heavy loads or driving in extreme conditions can contribute to overheating.

Digging Deeper: Common 2018 Highlander Transmission Problems

While the symptoms and causes listed above provide a general overview, let's delve into specific issues that have been reported by 2018 Toyota Highlander owners:

  • Harsh Shifting Between 2nd and 3rd Gear: Some owners have described a noticeable and uncomfortable jolt when the transmission shifts between second and third gear, particularly at lower speeds. This issue is often attributed to valve body problems or software calibration issues.
  • Hesitation During Acceleration: This problem involves a delay or lag in acceleration when pressing the gas pedal. This can be especially concerning when merging onto highways or needing to accelerate quickly.
  • Transmission Slipping at Higher Speeds: Some owners have reported the transmission slipping at higher speeds, resulting in a loss of power and potentially dangerous situations. This can be due to worn clutch packs or torque converter issues.
  • Complete Transmission Failure: While less common, some owners have experienced complete transmission failure, requiring a full replacement. This is usually the result of prolonged neglect or severe damage.

Is There a Recall? And What About Toyota's Warranty?

It's important to check if there are any active recalls related to the 2018 Toyota Highlander's transmission. You can do this by visiting the National Highway Traffic Safety Administration (NHTSA) website and entering your vehicle's VIN. If a recall exists, Toyota will typically notify you and perform the necessary repairs free of charge.

Regarding warranty coverage, the original factory warranty for the 2018 Toyota Highlander typically covered the powertrain (including the transmission) for 5 years or 60,000 miles, whichever came first. If your vehicle is still within this warranty period, transmission repairs may be covered. However, it's essential to review your specific warranty terms and conditions to understand what is covered and what is not.

Okay, How Do I Fix This? Your Troubleshooting Guide

If you're experiencing transmission problems with your 2018 Toyota Highlander, here's a step-by-step troubleshooting guide:

  1. Check the Transmission Fluid Level: Use the dipstick to check the transmission fluid level. If it's low, add the recommended type of transmission fluid. Important: Always use the correct type of transmission fluid specified in your owner's manual.
  2. Inspect the Transmission Fluid Condition: Examine the transmission fluid on the dipstick. If it's dark, dirty, or smells burnt, it needs to be replaced.
  3. Check for Error Codes: Use an OBD-II scanner to check for any error codes related to the transmission. These codes can provide valuable clues about the source of the problem.
  4. Consider a Transmission Flush: If the transmission fluid is dirty, a transmission flush can help remove contaminants and improve performance. However, it's crucial to have this done by a qualified mechanic, as an improper flush can cause damage.
  5. Consult a Professional Mechanic: If you've tried the above steps and the problem persists, it's best to consult a qualified mechanic who specializes in transmission repairs. They can perform a thorough diagnosis and recommend the appropriate repairs.

Preventing Problems: Keeping Your Highlander's Transmission Happy

Prevention is always better than cure. Here are some tips to help prevent transmission problems in your 2018 Toyota Highlander:

  • Regular Maintenance: Follow the recommended maintenance schedule in your owner's manual, including regular transmission fluid changes.
  • Use the Correct Transmission Fluid: Always use the type of transmission fluid specified in your owner's manual. Using the wrong fluid can damage the transmission.
  • Avoid Overloading: Avoid towing heavy loads that exceed your vehicle's towing capacity.
  • Drive Smoothly: Avoid aggressive acceleration and braking, as this can put extra stress on the transmission.
  • Address Problems Early: Don't ignore any signs of transmission problems. Address them as soon as possible to prevent further damage.
  • Consider an Auxiliary Transmission Cooler: If you frequently tow heavy loads or drive in hot climates, consider installing an auxiliary transmission cooler to help keep the transmission cool and prevent overheating.

Transmission Fluid: The Lifeblood of Your Highlander

Transmission fluid is crucial for the health and longevity of your Highlander's transmission. It lubricates the moving parts, cools the transmission, and helps to transmit power. Maintaining the correct fluid level and condition is essential.

  • Checking the Fluid Level: Locate the transmission fluid dipstick (usually near the engine or transmission). With the engine running and the transmission in park, remove the dipstick, wipe it clean, reinsert it fully, and then remove it again to check the fluid level. The fluid level should be between the "Min" and "Max" marks.
  • Inspecting the Fluid Condition: Examine the fluid on the dipstick. It should be a clear, reddish color. If it's dark, dirty, or smells burnt, it needs to be replaced.
  • Changing the Fluid: Follow the recommended fluid change interval in your owner's manual. Typically, this is every 30,000 to 60,000 miles, depending on your driving conditions.

Frequently Asked Questions

  • What type of transmission fluid does my 2018 Highlander use? Your 2018 Highlander typically uses Toyota WS (World Standard) automatic transmission fluid. Always consult your owner's manual for the most accurate information.
  • How often should I change my transmission fluid? The recommended interval is usually between 30,000 and 60,000 miles, depending on your driving conditions and owner's manual recommendations.
  • Can I change the transmission fluid myself? Yes, if you have the necessary tools and knowledge, but it's generally recommended to have it done by a professional to ensure it's done correctly.
  • What is a transmission flush? A transmission flush involves removing all the old transmission fluid and replacing it with new fluid, often using a specialized machine.
  • How much does it cost to repair or replace a transmission? Transmission repairs can range from a few hundred dollars for minor issues to several thousand dollars for a complete replacement, depending on the severity of the problem.

Wrapping Things Up

While the 2018 Toyota Highlander is generally a reliable vehicle, being aware of potential transmission problems and taking preventative measures can help you avoid costly repairs. Regular maintenance, proper driving habits, and prompt attention to any warning signs are key to keeping your Highlander's transmission running smoothly for years to come. If you suspect a problem, don't hesitate to consult a trusted mechanic for a professional diagnosis and repair.