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Will A Transmission Flush Fix This Shuddering Ford F-150? We Hear It All The Time That Flushing The Transmission Fluid Is A Waste Of Money. Or They Say It Will Just Make It Worse. We Decided To Test It With This F-150

Here is the truth about the differences between transmission flushes and transmission fluid change services and how you should decide which is the correct choice for your car or truck that includes this alternative procedure that works.

Suppose you have owned a car or truck that has experienced transmission problems such as rough shifting, slipping of clutch plates or a strange shudder. In that case, the odds are very high that an internet search has left you confused about the "Do a transmission flush" and "Don't ever do a transmission flush" advice advocated by many YouTuber sites, as correctly pointed out recently in a new YouTube episode from the Royalty Auto Service channel.

The problem, however, is not that the advice on either side of the fence is wrong, only that it is likened to looking for a single cure for a common ailment with varying differences in the stage of the problem regarding the overall health of the person or transmission.

Related article: Ford Mechanic Talks About Transmissions That Self Destruct

The Differences Between Transmission Flushes and Transmission Fluid Service

Transmission Flushes―It is not just anecdotal evidence that has been blown out of proportion on the internet by some overzealous YouTuber sites warning that transmission flushes are a scam and will cause your transmission to worsen (although there is some of that); closer to the truth is that while not always correct, these concerns, fears, warnings, etc., are not without some merit.

The concern with a transmission flush is that using high pressure combined with a transmission cleaning solvent will loosen buildups in the system, causing the foreign material to migrate and interfere with normal transmission operation, such as in the transmission valve body/electronic servos where the hydraulics are controlled.

Think of it as being similar to a carotid massage to the major arteries and veins in your neck, causing plaque to break free and migrate to your heart, lungs, or brain, where fatal damage can easily occur. A carotid massage is useful for stimulating the Vagus nerve and slowing down a heart with certain heart rhythm disorders, but it also runs the risk of being harmful.

Another concern is that foreign matter buildup in an older transmission might actually be keeping it alive because it provides some "stick" between worn transmission clutch plates. Remove that stickiness, and your transmission will slip, making a car owner's transmission problems worse.

Furthermore, there is room for scamming car owners with offers of flushing their transmissions at costs ranging from $400-$600 in cases when the garage knows you are best served if that money is spent instead toward a new or rebuilt or even a used transmission from a salvage yard at a cost ranging from several thousand dollars to several hundred dollars, respectively, but is more likely to successfully sell you on a flush service instead.

Transmission Fluid Drain Services―One option is to do a transmission fluid drain and replacement where a garage or DIY types drain the transmission, closes the drain, and then refills with new fluid. The plus is that it avoids the potential problem of pressure and transmission cleansers dislodging transmission foreign matter buildup. The con to this service is that you only replace 30-50% of the old fluid with new fluid. Most transmission fluid will not drain entirely but will remain trapped within the transmission system outside the transmission pan.

Garages will do a version of this referred to as a "transmission service," in which two rounds or more of draining and replacement are done, resulting in a higher percentage of new transmission fluid in your car. The con to this is that you will be charged the same amount or more than with a flush―depending on how many cycles of fresh transmission fluid are used.

These Transmission Fixes Have Caveats

However, there are caveats to flushes and drains. And that is, more often than not, what happens to an older vehicle being worst off after a transmission flush is most likely because the vehicle's transmission was on its way out anyway. In other words, its owner(s) failed to ensure proper transmission maintenance.

The other caveat is that car owners often incorrectly consider a transmission flush or drain to be a fix rather than preventive maintenance.

The sensible (and most affordable) recommendation for maintaining your transmission for as long as possible is to have a transmission fluid change every 30,000 miles as a prevention measure. In other words, a drain and replace service that will not result in 100% new transmission fluid will very likely prolong the transmission's health by keeping your fluid reasonably fresh. It may even lessen the amount of foreign matter circulating through the system.

The In-Between Transmission Flush/Drain Service

If you don't want to DIY your transmission fluid but are a firm believer in maintenance, an in-between transmission flush/drain service may be the best option if your car is relatively new (roughly 30-50,000 miles).

An example of this was recently shown on a Royalty Auto Service YouTube channel episode where the host demonstrates transmission fluid exchange on a 2017 Ford F-150 with 106,000 miles on it and is experiencing a clear case of transmission shudder.

What Is Transmission Shudder?

Transmission shudder refers to a vibration or shaking sensation that occurs during certain operations of an automatic transmission―typically when the transmission shifts gears or when the torque converter lock-up clutch engages. This issue can feel like the vehicle is briefly shuddering or vibrating, often described as driving over a rumble strip.

Symptoms of Transmission Shudder include:

  1. A noticeable vibration or shaking during gear shifts.
  2. Shuddering when accelerating, particularly in higher gears.
  3. Feeling like the car is "slipping" or "jerking" under load.
  4. The sensation may worsen when towing or climbing steep inclines.

In the worst case of a transmission shudder, the problem is due to mechanical wear and failure, which is expensive to fix.

In best-case incidences of transmission shudder, the causes are less mechanical and more on the fluid side of the transmission, such as:

  1. Insufficient fluid causes improper hydraulic pressure, leading to shudder.
  2. Old, dirty, or degraded transmission fluid that reduces lubrication and leads to shuddering.
  3. Using the wrong type of transmission fluid or incompatible additives can affect performance.

Back to Today's Video Instruction

The benefit of the recent Royalty Auto Service video is that it offers a variation of the flush and drain methods by combining the two using an automated transmission fluid pump that alternates removing old fluid and replenishing with fresh fluid while the engine is running.

Although not stated in the video, presumably, the transmission fluid is not under any additional pressure above the vehicle's normal operating pressures, whereas other garages specializing in transmission flushes could be using high-pressure apparatuses in their service centers.

Another benefit is that, not unlike treating a patient for a medical condition, their example is the least invasive and, therefore, preferable. Preferably financially for the vehicle owner because what we can glean from all of the reported cases of cars where flushing worked and cases where flushing caused harm is that there is no cutoff of when exactly a vehicle is a good candidate or a bad candidate for a less invasive procedure.

That said, follow along with the host to see how the procedure is done, how it was a success on the Ford F-150, and judge for yourself if spending less on a chance that a less invasive and less expensive procedure for your transmission is the right choice for you.

Will A Transmission Flush Fix This Shuddering Ford F-150?

 

For additional articles related to transmission problems in your car, here are three recommendations for your consideration:

  1. Truth About CVT Transmissions Reveals Reliability and Costs of Having One
  2. Used Cars with Serious Transmission Problems to Watch Out For
  3. This Toyota Truck Common Problem Can Destroy Your Transmission!

Timothy Boyer is an automotive reporter based in Cincinnati who currently researches and works on restoring older vehicles with engine modifications for improved performance. He also reports on modern cars (including EVs) with a focus on DIY mechanics, buying and using tools, and other related topical automotive repair news. Follow Tim on Twitter at @TimBoyerWrites as well as on Facebook and his automotive blog "Zen and the Art of DIY Car Repair" for useful daily news and topics related to new and used cars and trucks.

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