2 Causes of Noise Problems After Changing Transmission Fluid

Last Updated on December 19, 2019

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.

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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.

Therefore, you need a functional transmission if you are going to have the proper engine RPM and vehicle movement.

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.

Top 2 Causes of Transmission Noise After 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 hear noises coming from the transmission after they have changed their transmission fluid. This often makes them wonder why because they figure changing the transmission fluid would have prevented strange things like this from happening.

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

#1 – Varnish Deposits

When you have old 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 your filters will not get clogged.

#2 – Wrong Type of 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 more clunking 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 purchasing transmission fluid will not cost you that much money. You can purchase a 10-ounce bottle of synthetic transmission fluid for less than $20. 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 $120. So, you could be looking at a total cost of between $100 to $200 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.


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