Do mechanics recommend a transmission flush?

The short answer is that the recommendation for a transmission flush can vary depending on the vehicle, the transmission type, and the mechanic's assessment. While some mechanics may recommend a transmission flush as a preventative maintenance measure, others may advise against it, especially for certain types of transmissions.

Understanding Transmission Flushes

A transmission flush is a service where the old transmission fluid is completely drained and replaced with fresh fluid. This is different from a simple fluid change, where only a portion of the old fluid is removed and replaced. Proponents of transmission flushes argue that it can help remove built-up deposits and contaminants, improving the transmission's performance and longevity. However, critics argue that the process can also dislodge existing deposits, potentially causing issues in some transmissions.

Factors Influencing Transmission Flush Recommendations

• Transmission Type: Mechanics may be more cautious about recommending a flush for certain transmission types, such as continuously variable transmissions (CVTs) or dual-clutch transmissions, as the process could potentially damage sensitive components.


• Vehicle Age and Mileage: Older vehicles or those with higher mileage may be more prone to issues after a flush, as the process can dislodge deposits that have been holding the transmission together.


• Transmission Condition: If a transmission is already showing signs of wear or issues, a flush may not be recommended, as it could exacerbate the problem.


• Manufacturer Recommendations: Some vehicle manufacturers may have specific guidelines or recommendations regarding transmission flushes, which mechanics will typically follow.

Ultimately, the decision to perform a transmission flush should be made in consultation with a trusted mechanic, who can assess the specific needs and condition of your vehicle's transmission.

Alternatives to Transmission Flushes

If a transmission flush is not recommended, there are other maintenance options to consider, such as:

• Transmission Fluid Change: Regularly changing the transmission fluid, as recommended by the manufacturer, can help maintain the fluid's condition and extend the transmission's lifespan.


• Transmission Additive: Some mechanics may recommend using a transmission additive to help clean and condition the fluid, without the potential risks associated with a full flush.


• Preventative Maintenance: Keeping up with other recommended maintenance, such as regular inspections and addressing any issues promptly, can also help prolong the life of your vehicle's transmission.

By understanding the factors that influence transmission flush recommendations and considering alternative maintenance options, you can make an informed decision about the best approach for your vehicle.

Why do people say not to flush transmission?

Don't flush the transmission. Just drain the fluid and refill. Flushing forces fluid through at pressures the transmission wasn't designed for and can cause damage to the transmission.

Is it okay to never change transmission fluid?

You should always change transmission fluid, especially when it's old, as it prevents transmission failure. While some "lifetime" fluids don't require frequent changes, regular maintenance is crucial for longevity. Neglecting to change the fluid can lead to sludge buildup, poor performance, and expensive repairs or replacement.
 
Why you should change your transmission fluid

• Prevents damage: Over time, transmission fluid degrades and accumulates debris, which can clog internal passages and cause gears to slip or grind. 
• Maintains performance: Clean fluid ensures proper lubrication and cooling, leading to smoother shifting and preventing overheating. 
• Extends lifespan: Regular fluid changes, even in modern "lifetime" fluids, can significantly extend the life of your transmission. 
• Avoids costly repairs: A failed transmission can be extremely expensive to replace, often costing more than the car is worth. 

What to do if your fluid is old

• Perform a "drain and fill": If your transmission fluid has never been changed, especially on a high-mileage vehicle, a drain and fill is often recommended instead of a full flush. 
• Use a conditioner: In very old, dark fluid, consider using an automatic transmission conditioner before the fluid change to help break up sludge and varnish. 
• Follow the owner's manual: Always refer to your vehicle's owner's manual for the manufacturer's specific recommendations on change intervals and procedures. 
• Be aware of risks: A full flush is typically not recommended for high-mileage transmissions with never-changed fluid, as it could dislodge large particles that might cause issues. 

This video explains the importance of changing your transmission fluid: 1mScotty KilmerYouTube · Jun 25, 2018
When to change your transmission fluid

• Follow the schedule: Adhere to the maintenance schedule in your owner's manual, even for vehicles with "lifetime" fluids. 
• Consider harsh driving conditions: If you frequently tow, haul, or drive in severe weather or stop-and-go traffic, you should change the fluid more often. 
• Watch for signs of trouble: If you notice gear slippage, grinding noises, delayed shifting, or excessive vibration, get your transmission checked immediately. 

You can watch this video to learn about the risks associated with changing transmission fluid: 1mChrisFixYouTube · Apr 8, 2016

Is it worth it to do a transmission flush?

A transmission flush is worth it for preventative maintenance to keep the transmission running smoothly, but it is not recommended for high-mileage vehicles with a history of neglected fluid changes. While a flush can improve mild shifting issues, it can dislodge built-up sludge and potentially damage older or neglected transmissions by causing them to fail shortly after. A less risky alternative for neglected transmissions is to simply replace the fluid and filter, which is a lower-cost service. 
This video explains the difference between a transmission flush and a fluid change: 25sFixITYouTube · May 25, 2025
When a transmission flush is beneficial:

• Preventative maintenance: Flushes are most beneficial as a routine service to clean out old fluid and contaminants, which can extend the life of the transmission. 
• Routine service: For vehicles with consistent maintenance records, a flush is a good way to maintain performance, fuel economy, and shifting quality. 
• Mild performance issues: If your car has mild shifting hesitation or harshness, a flush can sometimes resolve these minor issues by removing old, contaminated fluid. 
• Frequent harsh driving: If you frequently drive in stop-and-go traffic, tow heavy loads, or drive in other harsh conditions, a flush at shorter intervals can be more beneficial. 

When to avoid a transmission flush:

• High mileage with no prior service: If your car has high mileage (e.g., over 100,000 miles) and the fluid has never been changed, a flush is risky. 
• Very dark or burnt fluid: If the existing fluid is dark and burnt-smelling, it indicates severe internal wear. A flush could dislodge hardened deposits and cause the transmission to fail prematurely. 
• Known transmission issues: A flush is a maintenance service, not a repair. It will not fix underlying problems and can sometimes make them worse. 

You can watch this video to see how a transmission fluid change is performed: 59sScotty KilmerYouTube · Jun 8, 2021
Alternatives to a flush:

• Drain and fill: For vehicles with high mileage and no history of service, a simple drain and fill with a new filter is a safer option. This replaces only a portion of the old fluid but is less likely to cause damage than a full flush. 
• Consult a professional: It is best to consult a mechanic to determine the right service for your specific vehicle, especially if you are unsure of its maintenance history. 

Can any mechanic do a transmission flush?

Any good mechanic can flush and replace the fluid, change the filter at the same time.