Kenworth T680 Automatic Transmission Issues: Quick Fixes

Kenworth T680 automatic transmission problems can be caused by low or contaminated transmission fluid, leading to gear shifting issues and rough performance. These issues are commonly experienced by drivers and may require maintenance to resolve.

Kenworth’s automatic transmissions, including those in the T680 model, can be prone to faults that impact the overall performance of the vehicle. Proper care and regular checks of the transmission system are essential to prevent and address any potential problems that may arise.

Stay informed about common transmission issues to ensure smooth operation and longevity of your Kenworth T680.

Common Kenworth T680 Automatic Transmission Faults

The Kenworth T680 is known for experiencing common automatic transmission faults, including issues with shifting gears and running smoothly. Low or contaminated fluid caused by leaks in the system is a top cause of problematic transmissions. Resetting the transmission can be done by clearing transmission faults.

Paccar transmissions have also been known to have trouble with shift stalks failing.

The Kenworth T680 is a reliable truck, but like any vehicle, it may experience automatic transmission issues. Understanding the Common Kenworth T680 Automatic Transmission Faults is crucial for timely diagnosis and repair.

Symptoms Of Transmission Failure

When dealing with automatic transmission problems in a Kenworth T680, watch out for warning signs such as:
  • Hard or delayed shifting
  • Transmission slipping
  • Unusual noises during gear changes
  • Dashboard warning lights related to transmission
  • Fluid leaks under the vehicle

Typical Error Codes And Meanings

In case of transmission faults, you may encounter error codes on the diagnostic system. Here are some common Kenworth T680 automatic transmission error codes and their meanings:
Error CodeMeaning
PO700Transmission Control System Malfunction
PO735Incorrect Gear Ratio Detected
PO731Incorrect Gear 1 Ratio Detected
PO732Incorrect Gear 2 Ratio Detected
Common Kenworth T680 Automatic Transmission Faults and associated symptoms, drivers and maintenance teams can address issues promptly to ensure the smooth operation of the vehicle.

Low Transmission Fluid Issues

One of the most common problems that can lead to automatic transmission issues in Kenworth T680 trucks is low transmission fluid. Insufficient or contaminated transmission fluid can cause the transmission to malfunction, leading to gear shifting problems and overall poor performance. Identifying and rectifying low transmission fluid levels is crucial to ensuring the smooth operation of the transmission system.

Identifying Fluid Leaks

Identifying fluid leaks is essential in addressing low transmission fluid issues. Look for signs of red or brown fluid puddles beneath the truck, which may indicate a transmission fluid leak. Additionally, pay attention to any unusual smells or noises, as these can also be indicators of a potential transmission fluid leak.

Steps To Refill And Check Levels

Refilling and checking transmission fluid levels is a straightforward process that can help address low transmission fluid issues. Follow these steps to refill and check transmission fluid levels:

  1. Locate the transmission fluid dipstick under the hood of the truck.
  2. Ensure the truck is on level ground and the engine is running.
  3. With the transmission in “Park,” pull out the dipstick and wipe it clean with a lint-free cloth.
  4. Reinsert the dipstick fully and then pull it out again to check the fluid level. The fluid should fall within the designated range on the dipstick.
  5. If the fluid level is low, carefully add the appropriate type of transmission fluid until it reaches the recommended level. Avoid overfilling the transmission.
  6. Secure the dipstick back in place and close the hood of the truck.

Resetting Your Kenworth Transmission

Are you experiencing automatic transmission problems with your Kenworth T680? Resetting your Kenworth transmission can help resolve certain issues and get your truck back on the road. In this guide, we’ll discuss when to consider a reset and provide a step-by-step procedure for resetting your Kenworth transmission.

When To Consider A Reset

If you notice erratic shifting, slippage, or other unusual behavior from your Kenworth T680 automatic transmission, it may be time to consider a reset. A reset can help clear any temporary glitches or errors that may be affecting the transmission’s performance. It’s important to note that a reset should be attempted only after ruling out other potential causes of the transmission problems, such as low fluid levels or mechanical issues.

Step-by-step Reset Procedure

  1. Park your Kenworth T680 on a level surface and engage the parking brake to ensure safety during the reset process.
  2. Turn off the engine and allow the transmission to cool down for a few minutes before proceeding.
  3. Locate the transmission reset button or switch, typically found near the gear selector or on the dashboard.
  4. Press and hold the reset button for 10-15 seconds to initiate the reset process.
  5. Release the button and wait for the transmission to complete the reset. You may hear a series of clicks or see indicator lights flashing during this time.
  6. Once the reset is complete, start the engine and test the transmission by engaging the gears and observing its behavior.

By following these steps, you can perform a reset on your Kenworth T680 automatic transmission and potentially address any underlying issues affecting its performance. If the problems persist after the reset, it’s advisable to seek professional assistance from a certified technician to diagnose and resolve the issues.

Kenworth T680 Automatic Transmission Issues: Quick Fixes


Paccar Transmission Problems

The Paccar transmission in Kenworth T680 trucks is known for its reliability and smooth performance. However, like any mechanical system, it can encounter specific issues that require attention. Understanding common Paccar faults and knowing how to address these specific problems is crucial for maintaining the efficiency and longevity of the transmission.

Common Paccar Faults

Several common faults are associated with Paccar transmissions in Kenworth T680 trucks. These issues may include:

  • Erratic shifting behavior
  • Transmission slipping
  • Failure to engage specific gears
  • Warning lights indicating transmission problems

How To Address Paccar Specific Issues

When encountering Paccar transmission problems, it’s essential to address them promptly to prevent further damage and ensure the continued smooth operation of the vehicle. Here are some steps to consider when dealing with Paccar-specific issues:

  1. Diagnostic Scan: Use diagnostic tools to identify error codes and pinpoint the root cause of the transmission problem.
  2. Fluid Check: Ensure the transmission fluid levels are adequate and the fluid is clean and free from contaminants.
  3. Software Updates: Check for available software updates and ensure the transmission control module is running the latest version.
  4. Professional Inspection: If the issue persists, consult a qualified technician with expertise in Paccar transmissions for a comprehensive inspection and repair.

Transmission Options For Kenworth Trucks

When it comes to choosing the right transmission for your Kenworth T680, it’s essential to understand the available options and the potential issues associated with them. The transmission is a critical component of any truck, and selecting the appropriate model can have a significant impact on performance and maintenance. Let’s dive into the transmission options for Kenworth trucks and explore the factors to consider when making this important decision.

Comparing Kenworth Transmission Models

Kenworth offers a range of transmission models for its trucks, each with its own set of features and potential concerns. Here’s a comparison of the primary transmission options available for the Kenworth T680:

Transmission ModelFeaturesPotential Issues
Automated Manual Transmission (AMT)Seamless gear shifting, fuel efficiencyElectrical and sensor-related malfunctions
Automatic TransmissionConvenient operation, smooth shiftingSoftware glitches, fluid leaks
Manual TransmissionDriver control, simplicityClutch wear, driver error

Choosing The Right Transmission For Your T680

When deciding on the ideal transmission for your Kenworth T680, several factors should influence your choice:

  • Performance Requirements: Consider the specific demands of your operations, such as long-haul or regional transportation, to determine the most suitable transmission type.
  • Maintenance Considerations: Evaluate the long-term maintenance needs and costs associated with each transmission model to make an informed decision.
  • Driver Comfort and Preference: Take into account the driving experience and ergonomic preferences of your drivers to enhance overall satisfaction and productivity.
  • Reliability and Durability: Research the track record of each transmission model in terms of reliability and durability under various operating conditions.

By carefully weighing these factors and understanding the nuances of each transmission option, you can make an informed decision that aligns with your operational needs and minimizes the risk of encountering transmission problems with your Kenworth T680.

Troubleshooting Gear Shift Problems

When it comes to the Kenworth T680 automatic transmission, gear shift problems can be a major inconvenience for truck drivers. Troubleshooting these issues is crucial to ensure smooth and efficient operation of the vehicle. Let’s explore some common gear shift problems and how to address them effectively.

Dealing With Gear Selection Issues

One of the most common gear shift problems in the Kenworth T680 automatic transmission is difficulty in gear selection. This can manifest as the transmission not engaging or struggling to shift into the desired gear. Low transmission fluid levels, faulty shift solenoids, or worn clutch components could be potential causes. To address this issue, it is essential to first check the transmission fluid level and quality. Replacing worn-out components and conducting regular maintenance can help prevent gear selection issues.

Replacing Faulty Shift Stalks

Faulty shift stalks can also contribute to gear shift problems in the Kenworth T680 automatic transmission. If the shift stalks are malfunctioning, it can lead to difficulty in shifting, inaccurate gear selection, or complete loss of gear engagement. When encountering these issues, it is important to inspect the condition of the shift stalks and replace any worn or damaged components. Additionally, proper calibration of the shift stalks can help ensure accurate gear selection and smooth shifting.

Addressing Persistent Transmission Faults

Dealing with constant transmission faults in the Kenworth T680 can be a frustrating and costly experience for truck owners. One of the most common issues faced by drivers is the occurrence of persistent transmission faults, which can lead to downtime and decreased efficiency. In this article, we will delve into the common automatic transmission problems in the Kenworth T680 and provide insights on how to address these issues effectively.

Investigating Constant Fault Codes

When faced with persistent transmission faults in the Kenworth T680, it is crucial to investigate the underlying causes of the constant fault codes. One common issue is the occurrence of fault codes related to sensor malfunctions, fluid pressure irregularities, or electrical system glitches. These fault codes can disrupt the smooth operation of the automatic transmission, leading to erratic gear shifts and reduced performance.

When To Seek Professional Help

If you are encountering persistent transmission faults in your Kenworth T680 despite troubleshooting, it is advisable to seek professional help. Certified technicians with expertise in Kenworth transmissions can conduct a comprehensive diagnosis to pinpoint the root cause of the persistent faults. Professional intervention is crucial to prevent further damage and ensure the seamless operation of the automatic transmission.

Kenworth T680 Automatic Transmission Issues: Quick Fixes


User Experiences With Kenworth Automatic Transmissions

When it comes to Kenworth T680 automatic transmissions, drivers have encountered various challenges and issues that impact their driving experience. Understanding common complaints and tips from experienced truckers can provide valuable insights for those navigating automatic transmission problems with their Kenworth trucks.

Common Complaints From Drivers

  • Constant transmission faults affecting performance
  • Difficulty in shifting gears smoothly
  • Issues with reverse gear causing the truck to buck
  • Transmission malfunction leading to gear change problems

Tips From Experienced Truckers

  1. Regularly check transmission fluid levels for optimal performance
  2. Address any leaks promptly to prevent low fluid levels
  3. Consult with a mechanic at the first sign of transmission issues
  4. Practice safe driving habits to minimize wear and tear on the transmission

Preventive Maintenance For Longevity

When it comes to ensuring the longevity of your Kenworth T680 Automatic Transmission, preventive maintenance is key. By following best practices and adhering to regular check-ups and service intervals, you can prevent common transmission problems and keep your vehicle running smoothly for years to come.

Regular Check-ups And Service Intervals

  • Schedule routine maintenance appointments to inspect transmission health.
  • Check fluid levels and quality to prevent issues caused by low or contaminated fluid.
  • Address any leaks promptly to avoid transmission damage.
  • Monitor for unusual noises or vibrations that may indicate transmission problems.

Best Practices For Transmission Care

  1. Follow manufacturer guidelines for transmission fluid type and change intervals.
  2. Avoid excessive idling to prevent overheating and wear on the transmission.
  3. Practice gentle driving habits to reduce stress on the transmission components.
  4. Ensure proper alignment and tire pressure to prevent unnecessary strain on the transmission.
Kenworth T680 Automatic Transmission Issues: Quick Fixes


Frequently Asked Questions

What Is The Most Common Cause Of Automatic Transmission Failure?

The most common cause of automatic transmission failure is low transmission fluid, often due to leaks. Low or contaminated fluid hinders smooth gear shifting and overall performance.

How Do I Reset My Kenworth Transmission?

To reset your Kenworth transmission, turn off the engine, wait for a few minutes, then restart the vehicle.

What Is The Problem With The Paccar Transmission?

The Paccar transmission has been subject to recalls due to shift stalk failures, resulting in constant transmission faults. Additionally, some Kenworth trucks using automatic transmissions have experienced problems, often caused by low or contaminated fluid. It is recommended to regularly check fluid levels and have any issues addressed promptly to avoid costly repairs.

What Automatic Transmission Does Kenworth Use?

Kenworth trucks use automatic transmissions from reputable brands like Eaton and PACCAR for reliable performance.

What Are Common Kenworth T680 Transmission Issues?

Common issues include gear shifting problems, transmission faults, and fluid leaks affecting performance.


To conclude, the Kenworth T680 automatic transmission problems can be a major headache for truckers. Low transmission fluid, contaminated fluid, and faulty shift stalks are common causes for these issues. It is important to stay on top of regular maintenance and address any transmission faults promptly.

While automatic transmissions may not be everyone’s preference, it is necessary to understand and troubleshoot any problems that may arise to ensure a smooth and safe driving experience. With proper care, the Kenworth T680 can continue to be a reliable and efficient truck for years to come.

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