What is a Transmission Flush? Cost and Process

The importance of a transmission flush often goes unnoticed until serious problems arise. It is a process that is important to the health and maintenance of your car, and if done properly, is an excellent preventative maintenance procedure. Check your owner’s manual for the proper maintenance schedule. However, if you feel there are certain problems with your vehicle such as odd noises or gear shifting issues, it might do more harm than good.

In This Guide


Transmission Flush MachineA transmission flush is a maintenance process where all of the oil in a transmission is removed, new oil (and sometimes cleaning solutions) is run through it using a special machine to push out grime and sludge and then it is filled up with new oil. The process is used to remove debris and sludge and replace 100% of the used oil with fresh, clean quarts.

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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.

Transmission Flush vs. Change Cost
Flush$125 to $250
Change (Shop)$80 to $150
Change (DIY)$40 to $90

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The cost depends on several factors including your car’s make and model, your location, the type of shop you go to, the machine they use and any additional services such as pan removal and filter replacement. For example, at a quick lube shop the cost ranges from $100 to $200, while a dealership will charge between $150 and $300.

Factors that Affect the Cost

  • Year, make and model of your car/transmission (high end cars cost more)
  • Your location (cities have a higher cost of living/labor)
  • Type of shop (quick lube, independent mechanic or dealership)
  • Type of flushing machine (pump inlet or cooler line)
  • Type of fluid used (synthetic is more expensive)
  • Amount of fluid required (11-21 liters)
  • Additional services (filter replacement, pan removal)

Note: We highly recommend choosing a service that includes pan removal and a new filter. This will add to the cost, but it will help extend the life of your transmission.


There are debates as to the effectiveness of this procedure. Some state that flushing your vehicle using professional equipment may actually damage your vehicle. They say that the gunk and residue that are being flushed out may actually get lodged somewhere where it shouldn’t be, which could cause failure sometime in the future. Some believe that valves and seals may be bent or weakened with the pressure some machines use to force cleaning solution and fluid through the lines.

On the other hand, most agree that it is a legitimate maintenance procedure for your vehicle. They believe that a flush can help remove residue and materials from the engine, improving its performance and its lifespan. Whenever you are considering having one done, consult your owner’s manual first, then your dealership or local service center.

Flush vs. Change

A flush uses a professional grade machine to completely flush all the transmission fluid from your vehicle and remove some grime and contaminants from the torque converter and cooler lines to prevent them from causing transmission problems. This process involves running a special solution through the lines until they come out completely clean and then fills up the system with new fluid.

A fluid change on the other hand simply drains it using natural gravitational forces. Not all the fluid in the system is drained using this method and it does not flush out contaminants. Most say it only drains between 20%-40% of the total volume.

The goal of both changes and flushes is to improve and extend the life and performance of your car.

Process – How it’s Done Properly

Before hooking your car up to the machine, a technician should take it on a test drive in order to recognize and diagnose any serious problems that should be looked into during inspection and servicing. The unit should also be inspected for any external signs of problems or leaks.

A professionally done procedure requires the use of specialized, government regulated machines. There are a few ways in which these machines differ in their performance and operation, but you can discuss the type of machine and method used with your mechanic.

Machines typically connect to the cooler lines. The line that connects your vehicle’s transmission to the cooler will be disconnected and attached to the machine’s line in. This will allow the car’s fluids to drain into the machine. The line out from the machine then connects to your car’s cooler. This allows the new fluid in the machine to be transferred into the vehicle. The transfer process only utilizes the pressure produced by the car’s pump to circulate it, so no damage can be done to the internal parts of the system.

As the old fluid side of the diaphragm fills, it pushes the new fluid diaphragm up, making it flow through the lines. It circulates just as it would under normal operating conditions, the only difference being that the incoming oil is perfectly clean and the outgoing liquid is gone for good. The one downside of this process is that due to the way that fluid cycles through the unit, some of it is dropped back into the pan without going to the cooler. This means that the old is not completely replaced, but is continuously diluted with new oil instead.

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Another method used is a pump inlet flush. This method attaches the machine’s line out to the pump intake. The process transfers fluid through the vehicle and into a drainage pan, completely flushing the system. When cleared, new fluid is supplied to fill up the car. This process requires the complete removal of your pan and filter and a new filter and pan are installed at the end. This requires more time, a few extra quarts of fluid (around 20) and costs a bit more, but it is a much more complete, ideal procedure.

Note: Some service centers use machines that add additional force to blast fluid and/or cleaning solution through the system. This is NEVER a good idea as this can damage seals and/or lodge sludge in places it shouldn’t be as mentioned above.

Used Pan and Filter

A complete service should ideally include removing the pan and inspection of the old oil to look for signs of current or near-future issues. Dropping the pan is important because the used fluid, what is lying in the pan and what is trapped in the filter will all tell you a lot about what condition it is in. Some of the gunk that is flushed ends up in the pan and is then sucked up into the filter. If the filter becomes too clogged, then the pump will starve for fluid, components will not get lubricated which leads to heat, friction, slippage and eventually failure.

Normally, and this varies between year, make and model, darkened oil with some debris or residue is normal. Metal flakes may be seen in the oil or the plug. However, if you notice an excess of gunk, grime, or metal flakes; if there is a burning smell or other unusual odors or the oil is black, it often means that your car has (or will soon have) some serious issues.

It is recommended to always have the filter replaced regardless of whether you’re getting a fluid change or flush (some vehicles do not have one that is replaceable). Some gaskets may still be “usable”, but it is always best to replace both filters and gaskets.

Overall, the key to maintaining a transmission is following exactly what is recommended in your vehicle’s owner’s manual. It will tell you whether you to get a flush or change and how often to have it done (after a certain number of miles or amount of time). Do not trust it’s health to something you read online or heard from a mechanic/service technician as some are just looking to get your money and do not care what is best for your transmission. (not saying all mechanics are dishonest, but they DO exist). Be sure to ask the person servicing your car to make sure they are following the proper procedures recommended above and in the manual.

Fluid Color Range

Note: Flushing and changing the filter are important preventative maintenance procedures, they are not a solution for ones that already have problems or are on the way to a problem according to their black, burned and/or high-debris-content fluid. Getting a flush when you think there might be a problem can do more harm than good and make it fail faster than it would have otherwise. The same applies for higher mileage vehicles that have never had their lines flushed.

By that time the damage has already been done and there is likely a lot of sludge and varnish built up inside. The fresh additives from the new fluid attack the deposits, causing them to break off and jam valves, clog passageways, etc. In that case the tranny is doomed anyway, so your best bet is to do nothing to it, set aside some cash, and drive it for as long as you can.


Types of Automatic Transmission FluidsThere are different types and grades that can be purchased and used in the exchange. Some of the most recommended are full synthetic fluids. However, certain vehicles and their parts may degrade with the use of full synthetic oil. This is usually the case for older makes and models. For the most part, full synthetic will lubricate better, combat heat and friction better and last longer. However, consult your owner’s manual or a service technician for the recommended type for your particular make and model of vehicle.

Important: Make sure that whoever is servicing your transmission uses the right type for your vehicle and not some cheap generic/universal version that could cause problems down the road.

How Often Should it be Done?

This maintenance procedure should be performed every 30,000 miles or so. Some service centers will advise doing it every two years or 24,000 miles. You can often review your owner’s manual or speak to your dealership, however it is important to understand your driving habits and relay that information to a professional. Vehicles that are often towing or drive through sand, dirt and other harsh terrain, may require earlier service. Consult a reputable service provider if you need advice.

Alternatively, if you don’t think it is safe enough, you want to save some money by doing your own maintenance or your owner’s manual recommends changing instead, you might want to consider changing it slightly more frequently than is advised to keep the oil in a more like-new condition.

Importance of Finding a Reputable Service Provider

A reputable mechanic will advise you on several aspects. They will determine if you even need one based on your driving habits, mileage and the manufacturer’s recommendations. They will also determine the proper method to use and will do the job professionally and properly; utilizing the proper kind for your particular make and model, not finishing until the fluid appears clean and clear, thoroughly inspecting what comes out of the car, replacing all gaskets and filters and properly installing all parts back onto your car so that it runs just right. In addition, they will do all this at a reasonable price and should back their work with a warranty.

In summary, this procedure is an easy, low cost maintenance option to perform on your car. It is essential over the lifetime of your vehicle in order to protect it from harmful damage cause by wear and tear. It is also a great indicator of the internal health of your vehicle and will prevent costly damage over time. Transmission repair can be quite costly so it is important to do your best to maintain a healthy, properly functioning transmission.

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27 thoughts on “What is a Transmission Flush? Cost and Process

  1. Getting a flush sounds like it would be good for the car. I’m going to have to look into that more. Maybe I’ll have that done next time I go in to get my car looked at. I wonder if my car has had it done before.

  2. I have a 2002 sport explorer. I’m a elderly lady and need my car for doctor appointments. The od light is blinking and sometimes it stops but starts again. I’m afraid and I have worn my elderly friends out for trips. Please can you help with advice.

    • Joan, If you have the 5R55E transmision with the 4.0L V6 motor. The most common problem when the OD light blinks is. Ford has an upgraded valvebody and valvebody seperator plate and gaskets. Average cost is $500 to $750. Ford made a redesign in 2004. If you have had problems that seemed as if the trans sliped from 2cnd to 3rd gear when accelerating, this is your problem. Best thing to do is, go to a reputable shop and let them plug the code reader into the OBD2 port. The code they get will most times give the answer. What ever the code. A good honest tech can diagnose properly. Wait to long and you might need $3000 for a transmission.
      Good luck

  3. I have 97 ford expedition and I can’t put it into park, but all the other gears work, I can put it into park from underneath the vehicle but that is really unsafe what could it be??
    my gear shift cables? or adjustment to the linkage bolts …..I don’t know this is my first vehicle…. is it my transmission going because the tranny fluid smells bad too?

    • I just noticed your comment online and wanted to respond. I have a 1998 Expedition with the same issue. If you look under the dash board, next to the steering column there is a plastic piece with two screws that hold the shift selector in place. The screws on these expeditions come loose and prevent you from putting it into the correct gear, and sometimes prevent you from starting the car. Just screws those back in with a torx wrench and see if that fixes your problem.

  4. I have a 2005 Nissan maxima se with 127,000 kmy transmission feels like its slipping its a automatic. I want to get it flush but mechanics and people is telling don’t touch it leave it alone.It might just get worse.

  5. Transmission work done properly must include a minimum warranty of parts and labor of two years or 24,000 miles. Rebuilding a transmission properly involves more than 10 hours of continuous work; labor rate in California – Los Angeles area – is about $85 – $110 per hour. When I see a complete rebuild for done for less than $2,000.00 is a red flag! People tend to fall for the cheap price, and within less than few months, transmission is out again with no warranty . Find a reputable auto repair in your area, AAA Shops, RepairPal, those are held to high standards.

  6. My 1982 ford f-100 won’t go into drive it’s automatic aND will go in reverse just fine but won’t even sense when it is in drive It just revs

    Please help me

  7. Jiffy lube flushed out the old and dirty transmission oil, my Plymouth 1998 voyager Van’s gear does not shift smoothty or if you push the gas pedal to run faster, the RMP level goes hgih so, the gear does not shift to a higher speed or the R<MP goes too high.. Do I need to replace the whole transmission or just need some fixing?

    • Most like they put wrong fluid, most dodge & chrysler use synthetic fluid i have seen this too many times especially those places quit lubes they hire young guys from high school that have no the experience and knowledge, after doing a flush the problem start.

  8. I had a 2003 Ford Explorer (V6). Went to Ford dealership to have the tranny fluid changed. I thought they’d be doing a pan-drop and filter replacement. Instead they flushed it, and wouldn’t you know it? Within a couple of weeks, my tranny started to malfunction (when hot). DON’T flush. Just drop pan, change filter, and top up with new fluid.

  9. Having the transmission flushed at any “quick oil change” shop is not a good idea. 15 or so years ago, I had a 1988 Honda Accord and had it flushed at a “quick oil change” shop, and after a month or two, the car became undrivable (had to rev it up to around 5,000 rpm to get it to move from a complete stop). Replaced it with 1999 Honda Accord, which I drove for 12 years with no problem. Took the 1999 Honda to a quick lube shop, had oil changed–They recommended a transmission flush; I declined the offer, but they did it anyway. After several months, car became undrivable (same symptoms as the 1988 Accord) and made loud grinding noise. Cost over $2,000 to get it fixed–the transmission mechanic told me the internal components were completely trashed. Got 50% repair cost returned from “quick oil change” head office. Moral of the story? Avoid those shops for anything but oil change service (they don’t do that right either). I have my professional mechanic do the oil changes and all car services. It costs more, and takes longer, but its worth it).

  10. I’m considering buying a 2010 Chevy HHR with 115,000 and am curious if I should have it flushed. I had my 2005 Pontiac Grand Prix flushed because they were known to have trouble so I did it as a preventative. I’m on a fixed income so I can’t afford to have major issues down the road from making the mistake of having it flushed with higher mileage and it never being performed before. I would appreciate any advice, I always counted on my father to help me with these decisions and he passed away.

    • Hello Lisa,
      Google “service bulletin 04-06-01-029E”. GM does not recommend transmission flush. If in doubt, consult a reputable mechanic in your area. If a transmission flush is not performed correctly, it will do more harm than good. Avoid “quick oil change” shop that offers transmission flush as they are not trained to do a proper transmission flush.

  11. I own a 2006 Max, When hot (driven for a a few miles) the car jerks and appears to be slipping when it’s trying to change gears. I purchased the car new and have never had a transmission flush. No warning lights ever appeared. Took the car to a reputable Transmission Shop, they hooked it up to a high tech machine and got no negative readings regarding the transmission nor did they receive any sort of negative reading. Could I just need a flush in that I’ve never had one performed? What could possibly be wrong with my car?

  12. I have a 2002 ford f-150 with 110,000 miles on it and am comsidering a BG Transmission service from our local Ford dealer. I’ve only had the truck for a few months and do not know anything about past maintiance. I have no problems with the Transmission now and if I do this will be doing it for preventative mantanice only. What do you recomand? Thank you for your comment.

  13. I’m blind in one eye so I shouldn’t have attempted this but I’ve changed my own oil many a time, replaced starters, batteries, spark plus wires & plugs, you know basic stuff……. I messed up cuz I couldn’t see. Thought inward at the right location. AFTER I DID THIS: I put no slip in my transmission fluid. I knew the minute I did it I was putting it in the wrong place. I know I need to flush the transmission but also I knew not to start it. So it hasn’t been STARTED since I did that dumb move. Lol …. I really need good advice on who or what to ask about flushing the transmission. Mind you, I never started he car so it hasn’t gone thru the car. Still in tank of transmission fluid.
    Thanks so much for your help.
    Much needed & very grateful.

  14. I bought a 97 Honda Accrd two weeks ago. The first time I drove it, it ran fine. Now when I drive it the check engine light stays on and sometimes it wont shift from 1st to 2nd gear. I had the code read off of the car and it came back to the trans and its supposed to be a electrical issue based on the code but could be caused by dirty fluid. The car has 163k. Should I do a fluid change or just prepare to replace the trans?

  15. I have a 2008 Ford Edge at 221k miles. No problems as we are pretty good with maintenance and it’s a trooper. However recently in COLD cold weather it jerks at certain points. Was suggested that I need the transmission flushed but I feel uncertain???. I hate the idea of taking it in and then something worse happening after it was maintenanced

  16. I have 2010 Jeep Liberty with 95,000 miles. The dealership recommends a transmission Flush… after reading the difference between the I guess I should make sure it is a fluid exchange? Scary never know who you can trust to do a proper job.

  17. I have a 2007 Chevy Malibu LT V6 3.5 Liter, 180750 miles…My transmission is slipping when it chànges gear and there is a humming noise when I accelerate pass 20mph and I can’t go over 65-70mph without a rumbling sound. I bought this car as is, and I wonder if a flush will help extend the life of the car untill I can afford further maintainace. I am a college student trying to make to work, class, and take my mom to her Doc appointments… Stress is REAL!!

  18. I have a Nissan Sentra 2001 automatic, 1.8L and about 180000 miles. this car won’t move when i park it over night. After starting the car and shifting the gear to D it will take like 5 minutes before it engages. i have recently changed my transmission oil as well still didn’t work. Kindly assist me the way forward.

    Thank you.

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