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Velvet Digest

Is a transmission flush bad?

Author

Ethan Hayes

Updated on June 18, 2026

And some people warn against performing a flush on a transmission using old, dirty fluid. The flushing procedure may cause some fluid to move in the opposite direction of normal flow due to eddy currents, which may increase the risk of dislodging debris and causing it to settle somewhere it shouldn't.

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Similarly, you may ask, are transmission flushes worth it?

If you do a lot of mountain driving or heave towing, then a flush would be necessary. Under normal driving conditions, a flush is NOT necessary at 46K miles. The shops make money on flushes, that's why they recommend them. Most transmissions are good for 100,000 miles before requiring maintenance.

One may also ask, can changing my transmission fluid be bad? Changing the fluid and filter is never a bad idea, as long as you use the correct parts, as there are many types of trans fluid - all with different characteristics.

Subsequently, one may also ask, why is a transmission flush bad?

If you do a flush when there is damaged transmission material in the transmission fluid, you could cause a problem in the valve body at the bottom of the transmission. If the valve body gets gunked up with damaged transmission material, you could lose the ability to shift between gears.

How do you flush your transmission?

Disconnect the hose that returns the transmission fluid from the cooler and place the end into a bucket full of fresh transmission fluid. Start the car and run the transmission back and forth through the gears a few times until the fluid coming out of the transmission looks clean or you are nearly out of fresh fluid.

Related Question Answers

Can you change transmission fluid after 200000 miles?

At 200k miles it is entirely possible the tranny fluid has a bunch of the friction material in it that helps ensure your transmission still works. Drain the fluid and you may lose that friction material.

Should I flush or change transmission fluid?

As you can tell by their names, a transmission flush and a fluid change are two completely different services. While a transmission fluid change focuses on draining the dirty fluid from the pan, a transmission flush gets rids of all the fluid in the pan, the cooler lines, as well as the torque converter.

Should I change transmission fluid after 200k miles?

The manufacturer's maintenance schedule for many automatic transmissions doesn't call for fresh fluid until 100,000 miles or, with some Ford transmissions, even 150,000 miles. A lot of mechanics say that is too long and that it should be done at least every 50,000 miles.

Should I change transmission fluid after 100k miles?

Yes, definitely, regardless of whether you have a manual or an automatic transmission. Manual: Most manufacturers recommend that manual transmission fluid be changed every 30,000 to 60,000 miles. The typical service interval is 60,000 to 100,000 miles. Changing it more often does no harm.

How long does a transmission flush take?

3 to 4 hours

How do I know if I need a transmission flush?

The 5 signs include: 1) strange noises or even grinding coming from the transmission, 2) you experience problems shifting gears, 3) you experience some slippage when shifting gears, 4) unexplained surging of you vehicle, and 5) delay in movement after placing the vehicle in gear.

Why You Should Never flush your transmission fluid?

Pressure flushing can cause aging seals to start leaking. When it leaks more than a quart it could burn up the unit. Flushing does not cause the transmission to fail but it may speed up the process because it pushed metal particles back through the system.

How often should you change transmission filter?

every 2 years

What should a transmission flush cost?

Average Cost and Factors The typical price range for a transmission flush is $125 to $250 – approximately twice as much as a fluid change due to the additional fluid required (12-22 quarts instead of 5-7 quarts) to completely replace the old fluid. The average you can expect to pay is $150 for the full service.

How much is a transmission flush at Jiffy Lube?

Jiffy Lube's $100 automatic transmission flush, done by entry-level people, is incomplete. They will not change the automatic transmission filter, a key part of the flush, but which also violates the corporate 15-minute service rule.

Does transmission fluid clean your engine?

Transmission fluid keeps the engine sludge free but the engine oil controls the sludge. Both have different properties. So, transmission fluid does not operate properly with the motor oil due to clutch and band slippage.

What does Lucas do for transmission?

Lucas Transmission Fix is a non-solvent formula that stops slip, hesitation and rough shifting in worn transmissions and completely eliminates most seal leaks. Use in any transmission for preventative maintenance. Use also in light duty manual transmissions to increase shifting ease and transmission life.

Is it good to change transmission fluid on high mileage?

Changing the transmission fluid on a high-mileage car is risky. Don't do it unless your transmission is running fine and the fluid is first-rate, because it can make transmission failure imminent.

Should you change transmission fluid in a sealed transmission?

A sealed transmission does need to have the fluid checked or replaced periodically. Auto techs can check the fluid of a sealed transmission through an access in the side of the transmission. Some may opt to remove the transmission pan to completely replace the transmission fluid, as well as the gasket.

Should I change my transmission fluid if it's black?

In a nutshell, if you see black transmission fluid, replace it with the right one, avoid flushing, and change all the transmission parts if there is a burnt smell. Use a dipstick to check the condition of the fluid at regular intervals.

How do you flush a torque converter?

Flush the Torque Converter
  1. Start the vehicle.
  2. Place a funnel at the mouth of the transmission dipstick tube.
  3. Move the transmission through each of the gears when about three quarters of the total fluid capacity of the transmission has been drained and replaced.

Is it necessary to change transmission filter?

Although every vehicle has its own maintenance schedule that can usually be found in the owner's manual, the transmission filter and fluid should be replaced every 30,000 to 100,000 miles.

When should I change my transmission fluid Honda?

What is the year, engine, and transmission type? Honda's earliest CVTs were recommended to have a fluid replacement every 15,000 miles; later versions combined with the improved fluid can go 60,000. Early manual transmissions that used motor oil as MTF should get fluid changes every 30,000 miles.

How does transmission fluid get into the torque converter?

Torque converters transfer power by using an engine-mounted turbine to push oil (fluid) through a transmission-side turbine until that turbine can no longer pass fluid without moving. Unfortunately, many torque converters can only be refilled while the transmission is already out of the vehicle.