2 Causes of Transmission Problems After a Fluid Change

Last Updated on June 2, 2022

The transmission of a vehicle is crucial for it to move and operate properly. The job of a transmission is to transmit power from the engine and deliver it to the wheels of the driving mechanism.

There is a gearbox connecting to the transmission which lets the driver change gears. When the gears are changed, the rotating power and speed in the engine are converted based on the demands being put on it.

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Like engines, the transmission contains many moving parts and components which constantly need to be lubricated. Transmission fluid is used to as a lubricant for these parts to keep them running smoothly and to cool them down in case they start to heat up.

After a while, your transmission fluid will get old and debris may start to build up in it. That is why most car manufacturers will recommend that you change your transmission fluid every 50,000 to 100,000 miles. This ensures the fluid is fresh and will not cause you any problems while out on the road.

Related: Transmission Fluid Color Chart

Top 2 Reasons For Transmission Problems After a Fluid Change

When you change your transmission fluid, you should not have any problems shifting gears or maintaining certain driving speeds. You also shouldn’t hear any unusual noises or experience any unusual symptoms.

However, there are cases when drivers will feel something wrong or hear noises coming from the transmission soon after they have changed their transmission fluid. This often makes them wonder why because they figure changing the fluid would have prevented strange things like this from happening.

So, why do these problems occur after the fluid has been changed? Below are two of the most common causes after a fluid change.

#1 – Varnish Deposits

burnt transmission fluid symptoms

When you have old or burnt transmission fluid, it may become discolored and cause varnish deposits to build up inside the system. These deposits typically float around the old fluid and don’t really build up anywhere as you continue using the same fluid.

However, once you change the old fluid with new fluid, these deposits get washed away and it becomes sludge that sticks to the filters of your transmission system. This prevents transmission fluid from flowing through the transmission, which results in those strange noises to be heard.

Therefore, you need to flush your transmission before adding new fluid. That is the best way to ensure that no pathways get clogged within the transmission.

See Also: 7 Symptoms of Overfilled Transmission Fluid

#2 – Wrong Type of Transmission Fluid

what color is transmission fluid

It is best not to use traditional transmission fluid that is petroleum-based because these will leave the most deposits behind. Once these deposits build up on your filter and restrict the transmission fluid from flowing, it will cause the transmission’s components to heat up and create more friction.

This will result in clunking and other noises that you don’t want to hear. Fortunately, there are synthetic transmission fluids which are formulated to ensure that these components stay lubricated and that the gears shift smoothly. You will find this fluid marketed as “trans medic” in most cases.

Related: How Often to Change Transmission Fluid

Transmission Fluid Cost

The good news is that changing transmission fluid isn’t horribly expensive. Expect to pay $40 to $100 for new fluid since most modern vehicles need anywhere from 5 to 15 quarts. You’ll also need a filter and possibly a new pan gasket. However, the hardest part for most people will be replacing the old transmission fluid with the new fluid.

For this, you may have to go to a mechanic and have them perform the job for you. This will mean paying their hourly labor charge of between $80 and $110. So at minimum, you’re looking at a total cost of between $150 to $250 when you get your transmission fluid replaced by a professional.

Also, you may need to have them clean and flush the transmission too, so you can ensure that those deposits built up in the system are removed.


29 thoughts on “2 Causes of Transmission Problems After a Fluid Change”

  1. I have maintained my 2016 Honda Accord 159,000 miles one owner regularly with the dealership. In April I had a transmission flush. Everything was good from what the mechanic said. Yesterday my transmission went completely out! No warning signs that I am aware of. The same dealership said there is metal all in my fluid. Can it happen that fast? Please help I feel like they are going to give me the run around

    • Yeah, I suppose it’s possible. Perhaps you didn’t notice the warning signs (for instance, hard shifting or a slight humming that wasn’t there before). It’s also possible something inside the transmission wore out over time. Maybe the shop in April put the wrong fluid in, or didn’t add enough transmission fluid. It’s hard to say without inspecting the failed transmission to determine the root cause of the failure.

    • Scotty Kilmer on Youtube said that the engine must be turned off when changing fluid or the transmission will be low on fluid and cut itself, unless it’s refilled simultaneously.

      • Had a transmission flush on a 2008 pontiac g6 gxp…6 speed auto.
        The next day,took it for a drive,let of the gas pedal,and when i pushed on it again,nothing…the car only revved up.
        I got no codes..no warning…
        Seems if i shut the car off,restart it it will move a short distance,then nothing again!!!!
        Is it possible,that something got clogged in the valve body,durning the flush????
        Car was running with any problems before i had this done.

  2. Hi interesting reading- have a problem hope you can help. Had automatic gearbox box of my 1960 Cadillac reconditioned after only 200 miles the pipe came off losing fluid stopped within 200 yards pipe reconnected new fluid added. Then after only about 2 miles transmission slips with not pull at all. Leave to cool will drive a gain until hot.
    I assume some damage done when lost fluid but just 200 yards thought be ok- can you advise on this

    • What is an AFT? Did you perhaps mean ATF? I will need more information about the problem before I am able to help.

      Were you running the vehicle while you were changing the ATF? When did the vehicle lose power? Were there any other symptoms such as a check engine light?

  3. So i add 2 1/2 quarts of transmission fluid to my 2003 nissian Xterra and its still having a hard time shifting 3000 rom what else could be the problem

    • There could be any number of problems with the transmission. Are you able to narrow the scope of the problem any further?

      Do you hear any strange noises? Are there any conditions that will make the problem better or worse?

  4. hi i changed my my gear oil yesterday for my nissan sentra . since i was facing low speed in my car , i changed the oil for gear box. after changing the gear box oil, my vehicle speed does not rise immediately. i need to give long acceleration, to rise. please advise why this happening.

    • I’m not sure I understand. Was the transmission changed twice? Was it replaced under warranty? If the transmission was replaced under warranty and the vehicle is running fine now, I’m not sure there is anything left to do.

  5. Should I drain & fill, flush & replace or leave the transmission fluid as is for a 2014 Cruze diesel (VIN 1G1P75SZ6E7101005) 150,000 miles that has never had any fluid changed?


    • Generally a flush at that high of mileage is not recommended, especially when the vehicle has never had its transmission fluid changed. This can sometimes cause transmission slipping, but check with a local mechanic or the factory service manual to be sure in your case.

      Are you experiencing any problems with the vehicle that made you want to try changing the transmission fluid?

  6. My 99 chevy silverado 1500 isnt shifting out of gear after changing the filter and fluid. It was having trouble shifting and technician said filter and fluid was due to ne changed.

  7. Just got humming sound with my 2007 Murano so checked with OBDII by mechanic and P0746 & P0868 got these code. So mechanic advised change the fluid & filter as car already done 100000km so did it but after change that car moving (hardly 1 or 2 metr forward/revers only) and lost its power. mechanic couldn’t find the reason. would you any advise to fix it… would be appreciated..!

  8. I recently had a mechanic shop give my car (2004 ford falcon BA) a transmission flush and service as they recommended that’s what needed to be done as car was getting hot, since found out the thermostat just needed changing and now doesn’t get hot but since the auto transmission was serviced and flushed by mechanic shop my car has suddenly started shuddering before every gear change why would that be??

    • How many miles were on the transmission when they flushed it? Why would they suspect you need a transmission flush when your car is overheating? Although automatic transmissions typically use the radiator to cool transmission fluid, those two issues seem completely unrelated to me.

      I’m pretty skeptical of this shop, given your description of the situation. I might consider looking elsewhere next time you need maintenance.

  9. Had transmission fluid changed and 2 weeks later car started smoking from engine. Was out of town ended up had to have fluid lines replaced. Shouldn’t they have been checked with initial job?

    • Were the fluid lines loose? Could the smoking have been caused by leaking transmission fluid, or spilled transmission fluid from the initial fluid change?


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