There are many critical fluids that help an automobile to keep functioning. From engine oil to windshield washing fluid, brake fluid to transmission fluid, it’s a veritable cocktail of liquids that keep all the hardware churning over nicely. In today’s blog, we’re focusing on the fluid that helps keep your gears going around, and that is, of course, transmission fluid. Among our many questions is the core idea of how much is too much transmission fluid in a car?
What is Transmission Fluid and What Purpose Does it Serve?
Your car’s transmission fluid is an important lubricating liquid in your car. It is usually a rich red in color with an element of transparency, and its main function is to offer lubrication to the many components of a car’s transmission. If your car is an automatic, then your transmission fluid is also an important coolant to help stop the system from overheating.
You’ll find the transmission fluid for a FWD vehicle under your car’s hood and quite close to the dipstick for the engine oil. For a RWD vehicle, it will be closer to the rear of the engine. In any case, it is clearly labeled and has its own removable dipstick that allows you to check the current color and consistency of the fluid. The ideal state is a rich but transparent red. If it’s leaning towards brown or dark brown, then it might need changing.
What Are the Symptoms of Having too Much Transmission Fluid in a Car?
Interestingly, it is quite possible to end up with too much transmission fluid in your car. There are some key signs that will show up if that is the case:
Dipstick Reads “Full”
As we mention above, the transmission fluid has its own dipstick like the engine oil does. If you pull out the dipstick you can quickly and easily check your current transmission fluid levels. If the reading is beyond the “full” level, or even at it, then you have a bit too much transmission fluid in there.
Leaking Transmission Fluid
Check the area around and under where the transmission fluid is in the engine. Are there signs of transmission fluid leaking? Look for pooled red fluid under the transmission dipstick port. You could also check around the pan gasket, cooler lines and torque converter seal for signs of leaks.
Unresponsive or Slow Acceleration
If you notice that your car is not responding when press down (even hard) on the gas pedal, the problem could be something known as “slipping transmission.” This is an issue when you have too much fluid in the system and the gears are falling out of sync and not engaging properly as they should.
Difficulty in Gear Shifting
Interestingly, it becomes harder to shift gears both when you have too much transmission fluid in a car and too little. When there is too much, you get a buildup of pressure that creates foam. That foam diminishes the lubricating qualities of the transmission fluid, thus making shifting gears a harder task to accomplish.
Strange Noises
Another sign that you might have overdone it with the transmission fluid is that you hear grinding or humming noises within your transmission system. Grinding could happen because of many issues, but in fact the more likely explanation is a lack of transmission fluid. When you have to much, you’re more likely to get the humming or whining noise. Any kind of strange or unsettling noise from the transmission (and the engine too) is cause enough for concern.
Engine Overheating
Finally, with the sluggish performance of the transmission being caused by excess transmission fluid, the engine will be working harder to compensate which can cause overheating.
How to Fix When You Have Too Much Transmission Fluid in a Car
There are two main approaches you can take if and when you discover that you have put too much transmission fluid in a car. The first is siphoning out the excess, and the second involves draining the transmission fluid and refilling again.
Siphon Out the Excess Transmission Fluid
Contrary to what you might have seen in TV shows and movies, siphoning does not involve you sucking out transmission fluid through a tube. A proper siphoning kit will come with a pump or possibly a syringe that will allow you to draw fluid out safely and hygienically.
Draining Transmission Fluid
Under your car there should be an overflow valve that you can open to drain your transmission fluid, catching it in an oil pan or other receptacle. This is not dissimilar to when you’re draining oil. Getting at the release valve under the car could be tricky if you don’t have jacks with which to lift the car.
How Much Transmission Fluid Do You Need?
Getting to the right level of transmission fluid is a careful process of filling and then inspecting the level until you get the optimum reading which is indicated on the dipstick. If you want the maximum safe amount, we recommend building up enough transmission fluid in half-quart pours until you are close to — but certainly not in excess of — the “full” indicator on the dipstick.
The typical capacity if somewhere between 9 and 13 quarts, depending on what kind of car you are driving. Add the transmission fluid about half a quart at a time, then start the engine and let it run for a few minutes. Check the dipstick to see its current level and then add or cease adding when you reach the optimum level.
How Often Should Transmission Fluid Be Changed?
Many manufacturers give their recommendation for flushing and changing the transmission fluid every 2 years or 30,000 miles, whichever is first. Some vehicles are hardier and can withstand continuous use of the same transmission fluid for 60,000 miles. To get your manufacturer recommendation, you can check your car owner’s manual.
If you encounter people who advise you that changing the transmission fluid is never really necessary, then they are wrong. The fact is that there is considerable heat generated when you are driving and this continuous heat eventually causes the transmission fluid to start losing its lubricating qualities, which hardens the seals, causes leaks and eventually losses in pressure. Keeping the fluid fresh and functional is among your top priorities.
Can You Change Transmission Fluid Yourself?
If you have the will, the confidence and the time to change your transmission fluid, as well as the proper tools, then there’s no reason you shouldn’t try it yourself. As a matter of course, however, and because it’s maintenance that involves a critical and complex system in your car like the transmission, we don’t recommend any amateur try to do this themselves. These tasks are always best left in the hands of the professionals.
Step 1: Lift the car with a car floor jack and locate the transmission fluid cap.
Step 2: Prepare a drip pan, oil pan or other suitable receptacle and place under the cap.
Step 3: Loosen the bolts on the transmission cap to allow the fluid to come out. It will likely gush from the moment you loosen it, so be ready. Take care also in case the fluid is hot.
Step 4: Replace the pan gasket and the filter
Step 5: Tighten the bolts back up
Step 6: Lower the car back down, pop the hood and fill up the transmission fluid reservoir via the port in the engine bay. Use a funnel to avoid spills.
Step 7: Start your engine and let it run for a few minutes, and then check the levels on the dipstick. Add more if necessary.
How to Read Your Transmission Fluid Color
Above we mentioned that the standard color for fresh transmission fluid is a rich but transparent red. This is what it looks like when it comes out of the bottle or whatever other container it is sold in. It might also be a rich pink color, depending on the brand. When the fluid starts to turn after thousands of miles of use, it will move towards a burnt brown color. See below for further reference.
- Bright Red or Pink – New fluid in excellent condition
- Reddish-Amber – Used, but still functioning well
- Dark Brown / Black – Expired and in need for replacement
There’s also the possibility that your transmission fluid will become a kind of milky pink or brown, and quite possibly carry a burnt odor. If it turns any off color and has a smell of being burnt, then it’s not just the fluid that’s having problems, but the mechanics of your car, too. Such a situation merits the attention of a professional.
Conclusion: Never Lose Track of the Transmission Fluid
Your transmission fluid is a critical component that keeps the gears moving and the overall mechanics of your car ticking over. You cannot afford to skip changes, cut corners or take liberties with the integrity of your transmission fluid. Look out for the warning signs mentioned above, and if you are ever in doubt, check the dipstick and make an appointment to see a professional technician.
