Understanding CVT Judder
CVT transmission is a relatively new technology compared to the traditional automatic and manual transmissions. These types of transmissions are considered the best option as they guarantee less fuel consumption, a smoother driving experience, and greater efficiency in torque transfer. However, there is a downside to these transmissions: they tend to develop a juddering or shuddering problem over time, popularly known as CVT judder or shake. This problem can cause anxiety and concern to drivers, as they start to feel as if their vehicle has developed a significant mechanical fault.
CVT judder is a diverse problem, as it can occur from low-speed, high-speed, during acceleration, or even deceleration. The shaking feeling is a result of the metal belt slipping over the pulleys instead of smoothly rotating. The problem also varies from one vehicle model to another, meaning there is no universal solution. Drivers must be informed and have a basic understanding of CVT judder and its causes to troubleshoot the problem effectively.
The wrong driving practices are among the leading causes of CVT judder. For instance, some drivers like to hit the gas pedal hard, forcing the transmission to instantly increase the engine’s RPM. This sudden increase in RPM causes the moveable pulleys to move faster than expected, resulting in the slip of the belts over the pulleys, causing judder. Similarly, some drivers tend to brake the car while accelerating, causing hesitation in the transmission, causing the same judder.
Other causes of CVT judder may include a worn-out metal belt, an inconsistency in transmission fluid, or damaged torque converters. A worn-out metal belt may result from the lack of proper maintenance, which causes the belt to lose its elastic properties and slacken over time. An inconsistency in transmission fluid is when the fluid is dirty, outdated, or low in quantity, causing the transmission to lose its lubrication, which in turn affects its efficiency. Lastly, the torque converter can be damaged by several factors such as overheating, worn-out, or internal mechanical failure.
In conclusion, CVT judder is a problem that affects many vehicle models that use transmissions with a CVT system. However, drivers can avoid this issue by practicing good driving habits, following the recommended maintenance practices, keeping the transmission fluid levels at optimum levels, and getting their car inspected regularly. Additionally, drivers should not neglect any warning signs that their car may exhibit, such as unusual noises or vibrations. Once drivers understand the causes of CVT judder, they can take the necessary steps to avoid and fix the issue.
Inspecting the CVT System
When it comes to CVT judder, it’s important to inspect the system thoroughly before taking any steps towards fixing the problem. A quick visual inspection won’t be enough to diagnose the issue and all related components of the CVT should be inspected to prevent further problems down the line.
When inspecting the CVT system for potential causes of judder, there are a few things to keep in mind. Firstly, check the condition of the CVT fluid. If it’s dirty or low, this can create problems with the system. If the fluid is dirty, a simple fluid flush may be all that’s needed to fix the issue.
Next, inspect the CVT belt for any damage or wear. As the belt is responsible for transmitting power from the engine to the wheels, any damage or wear can cause issues with the CVT system. Check for any missing teeth or excessive wear and replace as necessary.
After checking the fluid and the belt, it’s important to inspect the drive pulleys and chain. Excessive wear or damage to either component can cause issues with the CVT system, leading to judder or other problems. Look for cracks or chips in the pulleys and check the chain for any signs of stretching or wear.
Another important factor to consider when inspecting the CVT system is the torque converter. If the torque converter is damaged or has excessive wear, this can cause judder. Inspect the torque converter for any signs of damage or wear and replace as necessary.
Finally, check the CVT valve body for any damage or issues. The valve body is responsible for controlling the hydraulic pressure and fluid flow within the CVT system, so any problems with it can lead to judder or other related issues. Inspect the valves and seals for any signs of damage and replace as necessary.
In summary, inspecting the CVT system is an important step towards fixing judder. Checking the fluid, belt, pulleys, chains, torque converter, and valve body can identify potential causes of judder and ensure all related components are in good condition. By thoroughly checking the system, you can prevent further issues down the line and keep your CVT running smoothly.
Reprogramming the Transmission Control Module
If you’re experiencing CVT judder, reprogramming the Transmission Control Module (TCM) is a good option. The TCM is responsible for controlling the operation of the transmission, and it determines the shift points and the timing of the shifts. It’s possible that the TCM is not operating correctly, which could lead to CVT judder.
Reprogramming the TCM involves updating the software that controls how the TCM operates. This can be done at a dealership or an independent repair shop. The technician will use a diagnostic tool to connect to the TCM and upload the new software. The new software will improve the TCM’s performance and may resolve the CVT judder issue.
When reprogramming the TCM, it’s important to use the correct software and to follow the manufacturer’s instructions. The software must match the vehicle’s make, model, year, and transmission type. Using the wrong software or making a mistake during the reprogramming process could cause other issues with the vehicle.
It’s also possible that the TCM needs to be replaced. If the TCM is damaged or not functioning correctly, reprogramming may not resolve the CVT judder issue. A technician can diagnose the TCM to determine if it needs to be replaced.
Reprogramming the TCM is a relatively simple process, but it’s important to have it done by a professional. If you’re experiencing CVT judder, have your vehicle inspected by a certified technician. They can diagnose the issue and recommend the best course of action to resolve it. In some cases, reprogramming the TCM may be the solution, but in other cases, other repairs may be necessary.
Finally, reprogramming the TCM is not a permanent fix for CVT judder. If the underlying cause of the judder is not addressed, it’s likely that the issue will return. The TCM may need to be reprogrammed periodically as part of routine maintenance. Regular maintenance, including oil changes, filter replacements, and inspections, can help prevent CVT judder and other transmission issues.
Replacing the CVT Fluid
One of the most common causes of CVT judder is degraded or contaminated CVT fluid. If you’re experiencing judder during low-speed acceleration or deceleration, there’s a good chance that you simply need to change your fluid. Here’s how:
- Get a drain pan and tools- You will need a socket set, a proper drain pan for catching the fluid, and a new filter that will fit your car’s make and model
- Lift your car- You will need to access the drain bolt located underneath the car. To do this, safely lift your vehicle using a lift or jack stands and follow proper safety procedures while lifting
- Drain CVT fluid- Unscrew the drain plug in the pan with a socket wrench and drain the fluid into the pan. This may take a while, so be patient and allow the fluid to drain completely
- Replace Filter- In order to change the filter, you must remove the drain bolt and push the filter down and away from the pan with a screwdriver or similar tool
- Replace fluid- After replacing the filter and attaching the drain plug, you must refill the transmission with the proper type and quantity of fluid, which can usually be found in the owner’s manual. Start the engine and check the fluid level with the dipstick to ensure proper levels
It is important to note that if you’re experiencing judder, you should also inspect and replace your CVT belt if necessary. A worn or overstretched CVT belt could also be contributing to your juddering problem. Although changing CVT fluid is not a complicated task, it’s important to follow the manufacturer’s guidelines and dispose of the old fluid in an environmentally-friendly way.
Rebuilding or Replacing the CVT Assembly
When it comes to fixing CVT judder, you have two main options: rebuilding or replacing the CVT assembly. It’s important to keep in mind that each option has its advantages and disadvantages, and the most appropriate option depends on your specific situation. In this section, we’ll break down each option in detail, so you can make an informed decision.
Rebuilding the CVT Assembly
Rebuilding the CVT assembly involves disassembling the transmission and replacing the worn out or damaged parts. This option is usually cheaper than replacing the entire assembly and is a good choice if most of the transmission components are still in good shape. Here are some steps involved in rebuilding your CVT assembly:
- Remove the CVT assembly from your vehicle
- Disassemble the transmission and inspect the parts for damage
- Replace any damaged or worn out parts (e.g. bearings, seals, clutches, etc.)
- Clean and reassemble the transmission
- Install the rebuilt CVT assembly back into your vehicle
If you have the knowledge, experience, and tools, you can attempt to rebuild your CVT assembly on your own. However, this option can be time-consuming and complex, so it’s best left to professional mechanics.
Replacing the CVT Assembly
Replacing the CVT assembly is a more straightforward option, but also more expensive. If your CVT assembly is severely damaged or worn out, this is likely the best option. Here are some steps involved in replacing the CVT assembly:
- Remove the CVT assembly from your vehicle
- Obtain a replacement CVT assembly
- Install the new CVT assembly back into your vehicle
It’s important to note that when replacing a CVT assembly, you should use a brand new or remanufactured assembly. Used assemblies may have the same defects as your old one, so they should be avoided.
Which Option is Right for You?
As mentioned earlier, the most appropriate option depends on your specific situation. Here are some factors to consider when deciding between rebuilding or replacing your CVT assembly:
- Cost: Rebuilding a CVT assembly is usually cheaper than replacing it, but it may not be worth it if the transmission is severely damaged.
- Time: Rebuilding a CVT assembly can take several days or even weeks, while replacing it is usually faster.
- Quality: A remanufactured CVT assembly should have the same quality as a new one, while a rebuilt assembly might not.
- Warranty: A new or remanufactured CVT assembly usually comes with a warranty, while a rebuilt one may not.
- Expertise: Rebuilding a CVT assembly requires knowledge and experience, so it’s best left to professional mechanics.
By considering these factors, you can make an informed decision on whether to rebuild or replace your CVT assembly.
Conclusion
Fixing CVT judder can be a daunting task, but by choosing the right option (rebuilding or replacing the CVT assembly), you can get your vehicle back on the road in no time. Whether you decide to do it yourself or have it done by a professional mechanic, make sure to choose a reliable source for your CVT assembly and follow the appropriate steps to ensure a quality repair.