Transmission Fluid Change vs Flush

When a vehicle owner drives into any car maintenance facility, they may or may not know what services they really need to keep their car running smooth and efficiently.  It’s easy to be taken advantage of.  They may need the technician to explain a little bit more about the ins and outs of maintaining their vehicle. Particularly, when they are not familiar with the differences between a transmission flush vs a transmission (fluid) change.


The transmission is just not a part of the vehicle which is serviced often, and as such people often don’t have a very good idea of what service it needs.  It’s a great idea to know as much about a transmission flush vs change as possible before you roll into the shop.


Knowledge is power.  You don’t want to get a flush if it is not something that the manufacturer calls for in the routine maintenance schedule.  That is unless the transmission has been under heavy stress, such as towing, hauling, or racing.  With that said, here is a brief overview of each.


 Transmission Fluid Change vs Fluid Flush

transmission flush vs change

Although these services use different names, a fluid flush and a fluid change are 2 completely different services. Particularly, because when the vehicle owner asks for a transmission fluid change, the maintenance technician will concentrate their efforts on draining out all of the dirty fluid from the transmission, while a transmission flush is meant to get rid of all the fluid inside of the pan, the torque converter and its cooler lines. So, there is a significant difference in which one the vehicle owner chooses.


Above, we listed the physical differences.  But, just as important, there are heavy cost differences.  A transmission flush is significantly more expensive than a fluid change.  Is it even necessary to pay the extra money for the flush?  They need to give you good reason that justifies the flush, such as:


  • Metal shavings in the pan.  This may mean that your transmission is doomed anyway, but shavings will finish it off quick.
  • The factory maintenance schedule calls for it.  It is not often that they do call for a flush anymore, but as vehicles creep into extremely high mileage situations, the manufacturer may call for it.
  • There’s burnt transmission fluid.  If the technician can show you that your transmission fluid is burnt, a flush may be warranted.  You should still check the fluid yourself for a burnt condition.  Pull the dipstick and make sure that the fluid is actually a dark color.  Make sure to deposit that transmission fluid onto a white paper towel or piece of paper.  If you are shown your clean fluid on a shop towel, it is certainly going to look darker than it really is.  Here is a fantastic guide that covers what does the color of your transmission fluid mean.
  • Your car has been used in a heavy-duty fashion.   Heavy duty If your car has been used for something like driving for über causes the same wear and tear on the vehicle that a taxi does.  Therefore, the transmission should be treated just like a taxi’s.  This means a frequent maintenance schedule that involves flushes when they normally wouldn’t be done.


Here are some reasons not to get a flush:

  • Your manufacturer may not want you to.  The company that made your vehicle is definitely going to want what’s best for your vehicle.  Vehicle longevity is big selling point.  One manufacturer that has a stellar reliability record is Honda.  They typically recommend that you drain out a portion of the fluid and replace that amount to not shock the system.  As your fluid circulates around the clutches and servos it gets (for lack of a better term) seasoned.  This seasoned oil can really develop a life of its own.  By replacing a small portion of it, you are insuring that there will be no shock.
  • It’s typically very costly, much more so than just getting the change done.  If there is no reason to get one done that you can justify to yourself, just get it changed.


Transmission Fluid Change


When the maintenance technician does a fluid change, their responsibility is to make sure the pan is completely drained and the transmission filter is replaced. In this process, all of the fluid will not be removed.   Especially because a huge chunk of this fluid will be left inside the torque converter as well as the cooler lines. It is also important to note that there are both pros and cons to this service and they are listed as follows:



  • It is significantly more affordable than getting it flushed.  Since most of us have to watch where are money is going, the change (or partial change) is the cost-effective option.
  • Vehicle owners can teach themselves to do the transmission fluid change themselves.  It’s not that difficult to do, especially if the transmission involved has a fluid drain plug.  Not all of them do.  If changing your own oil is a 3 out of 10 in the difficulty arena, than changing the transmission fluid is about a solid 5.  Still doable.  If you are going to give it a shot, practice a few times by getting comfortable with changing the oil yourself.



  • You won’t get all of the old fluid out.  If there has been an issue that leads you to believe that you may have harmed the transmission, such as low transmission fluid or drag racing, a flush may be more appropriate for your vehicle.




Some people may say that the transmission flush is superior to the fluid change. Specifically, because none of the old fluid is left behind. Therefore, any contaminates that could adversely affect the transmission are no longer a threat to its proper functioning.

All things being equal, many vehicle owners would prefer a flush and not a change. With a flush, all of the fluids are removed from the pan, cooler line and the torque converter. As a result, the new transmission fluid is not mixed with any of the old dirty fluids. Meaning the transmission will perform at its peak efficiency.

Before a vehicle owner takes their car in for transmission servicing, it is essential that they understand the differences between a transmission fluid change and a transmission fluid flush. Since both of which have pros and cons, people should make sure that they understand an overview of each so that they can make an informed decision.