What’s The Difference Between A Transmission Flush And A Fluid Change?
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Transmission Flush should it be done?
When changing transmission fluid, is it better to flush or pan drop?
What’s the Difference Between a Transmission Flush and a Fluid Change? When changing transmission fluid, is it better to flush or pan drop? Each method has its advantages and disadvantages. Read to learn more.
There is no one-size-fits-all solution. First, check your vehicle’s owner’s manual to see if it recommends one over the other. A transmission flush will remove nearly all of the old transmission fluid.
Here is what we’ll talk about:
What does “Transmission Flush” mean?
What can go wrong with a transmission flush?
What is a Machine for Flushing the Transmission?
Cost of a Transmission Flush
Cost to Change Transmission Fluid
Pan-Drop Change the transmission fluid
Tips on How to Do a Pan-Drop
It is possible and, to be honest, not that hard to drive farther on a gallon of gas. Using less gas saves you money and helps the environment by cutting down on pollution.
What does “Transmission Flush” mean?
The benefits of a flush are obvious: all of the old, dirty fluid is removed and replaced with new, clean fluid. And, as you can see in the picture, it’s better to use new transmission fluid than old fluid.
Because of this, your transmission should run cooler and the clutches, gears, and bearings should be protected as much as possible from wear.
Since the new fluid has the right frictional properties, it should also shift smoothly and quickly (old fluid loses its frictional properties over time). In fact, worn fluid is sometimes the cause of a transmission that shifts hard, hesitates, or jerks.
In addition to that, a flush helps clean the transmission.
Extreme heat can break down the fluid, which can cause sludge and other contaminants to build up in it. Before getting stuck in the filter, these contaminants move through the transmission.
Before the filter can safely catch the contaminants, though, they can get stuck in the small fluid passages inside the valve body. This makes the shifts not as good as they could be.
During a flush, you can also use a flush additive to help clean the transmission and get rid of sludge and other dirt that has built up.
An Inside View of the Innerworkings of an Automatic Transmission
AMSOIL talked to an industry expert to get an inside view on the innerworkings of an automatic transmission. Check out and hear what he had to say.
What can go wrong with a transmission flush?
One reason is that it costs more. Some people say that you shouldn’t flush a transmission with old fluid that is dirty.
Due to eddy currents, the flushing process could cause some fluid to move in the opposite direction of normal flow. This could make it more likely that debris will be moved and end up where it shouldn’t be.
What is a Machine for Flushing the Transmission?
A typical flushing machine has hoses that connect to the transmission cooling lines. It takes out the old fluid and keeps it in the machine while new fluid is put into the transmission.
A flushing machine, unlike a simple pan-drop, gets rid of almost all of the old fluid, including the fluid in the torque converter.
Cost of a Transmission Flush
Since the flushing process involves using new fluid, it takes more fluid than the transmission can hold. Plus, the reservoir and lines of the flush machine need to be filled with more fluid. The pump is also primed with some fluid. Most of the cost comes from those extra quarts.
How much it will cost to flush your transmission will depend on a few things:
The total fill capacity of the transmission
Where the service is done for you
How much the transmission fluid costs
Say you have a small car that needs about 8 quarts of transmission fluid. You take it to the dealership for service and they use OEM fluid, which costs about $20 per quart. They also change the filter and pan gasket on the transmission.
Depending on where you live, a transmission flush will probably cost about $250 in this case.
But let’s say you roll in a RAM 2500 that needs more than 15 quarts of transmission fluid. To flush the transmission, you can quickly spend more than $400.
But independent mechanics usually charge less than dealerships, which makes the math more complicated.
Depending on the size of your car and whether you go to an independent mechanic or the dealership, your transmission flush could cost anywhere from $150 to $400.
Keep in mind that many repair shops and quick lubes are picky about the fluids they use in their flushing machines, so it may be hard to find one that will use customer-supplied fluids.
To avoid cross contamination, flushing machines need to be cleaned between products
Cost to Change Transmission Fluid
So, how much is it to change the fluid in the transmission?
Again, it depends on the size of the transmission, where the service is done, the cost of the filter and gasket, and the cost of the fluid. A pan-drop will cost less than a transmission flush because it needs less fluid.
Here, I’ll talk about what I know from my own experience I took the pan off of my Toyota Camry, drained about three quarts of fluid, and replaced it with AMSOIL Signature Series Synthetic Automatic Transmission Fluid. I also replaced the filter (the gasket was still good), which cost about $60.
I could have paid less if I had used AMSOIL OE Synthetic Automatic Transmission Fluid, which is made for cars and trucks, but I think a Toyota Camry needs a fluid that is over-engineered for towing and hauling.
Let’s now use the heavy-duty diesel pickup that my in-laws use to pull a camper around the country.
A pan-drop needs seven quarts of fluid and a larger, more expensive filter. Since they aren’t as handy as I am, they’ll have to pay a mechanic another $100 or so. This means that the cost to change their transmission fluid will be about $275.
Again, the price of a transmission fluid change will depend on the size of your car, who does the work, and how much the filter and gasket cost.
If you do it yourself on a small car, it will cost between $50 and $75. Pay a dealership $200–$300 to change the fluid in your heavy-duty truck. This is especially true if you use OEM fluid.
Pan-Drop Change the transmission fluid
If you don’t like the idea of a flush, try a pan-drop instead.
Even though a pan-drop lowers the risk of flushing old, dirty fluid through the transmission, it also has some bad effects.
Only about a third of the fluid is taken out, which makes the new fluid less effective. The general rule is that you need 3 pan-drops to get rid of most of the old fluid, which can take some time.
Can also be a mess and take a lot of time.
Some cars may have trouble with it.
From my own experience, I can tell you that a pan-drop can be harder than you think.
To get to the transmission pan, you may have to take off plastic splash guards or metal skid plates.
If you haven’t looked under your car in a while, you can expect to find rusted and stuck bolts if you drive in snowy or wet weather.
Don’t be surprised if you break a splash guard when you try to take it off or put it back on.
Tips on How to Do a Pan-Drop
- Get a big pan to catch the fluid. If you don’t loosen the pan bolts, fluid will leak from where the pan meets the transmission and mess up the floor.
- If you’re clever, you can loosen the pan bolts in one corner more than the other bolts, tilting the pan so the fluid drains from one corner instead of the whole pan. This makes a lot less mess.
- Wear gloves and safety glasses.
- Don’t forget the new filter and pan gasket.
- Know the torque specs for the pan bolts and use a torque wrench to put them back in. If you don’t, you could overtighten and damage the gasket.
You can try this technique to change your transmission
Some car companies put a drain plug on the transmission, similar to how they put a drain plug on the motor oil.
This lets you easily and cleanly drain some transmission fluid without having to take the pan off. Still, you can only get between a third and half of the fluid out.
The car can then be driven for a while, the fluid can be drained, and the oil can be changed again. If you do this about three times, you’ll get rid of most of the old fluid and do a poor man’s transmission fluid flush.
Bottom line: If you want the best results and the least amount of trouble, take your car to a professional and have the transmission flushed. This is especially true if the transmission has been treated roughly and hasn’t been maintained well in the past.
But a series of pan-drops works just as well if you don’t trust a flush to get rid of debris or if the transmission has been well taken care of.
Why AMSOIL? Superior protection against wear, improved fuel economy and better performance under extreme temperatures. AMSOIL is the only oil that is able to last up to 25,000 miles. Save yourself time and money and protect your car or truck by using AMSOIL products. Your vehicle will last longer and you will lower your maintenance expenses. Protect your Honda, Toyota, Nissan, Chevrolet, Ford, Chrysler or any other vehicle with AMSOIL synthetic oil!
We advise you to consult your owners manual for proper fluid recommendations and to consult the appropriate repair manual for proper maintenance procedures and specs. Follow all appropriate safety practices. We are not responsible for misuse of products.