Did you know that if your mileage is between 30,000 to 60,000 then your car may be giving out signs of low transmission fluid?
I’m sure most of you may be worried after hearing that, but don’t worry, checking your transmission fluid levels and fixing it is easy.
Your transmission fluid should not only be on the correct levels but also clean. Transmission fluid that has gone bad or isn’t in the correct amounts can lead to problems in shifting and engaging gears.
The purpose of the transmission fluid in your car is to cool and lubricate the parts of your transmission. It is also used to facilitate hydraulic pressures and actuators. All of this translates to a quicker and smoother transmission at all times.
In this article, we are going to tackle the causes and symptoms of low-transmission fluid to help you diagnose and fix the problem quickly.
What is Transmission Fluid?
To understand why transmission fluid needs to be checked as part of a regular maintenance routine, it helps to know what it does.
Many car owners believe that the fluid’s only purpose is to lubricate the moving parts inside the transmission. While that’s true, there are additional functions it performs.
Transmission fluid:
- Lubricates moving parts to prevent wear, as mentioned.
- Reduces friction between components to improve efficiency.
- Cools parts to prevent overheating and damage.
- Acts as hydraulic fluid for the valve body to change gears.
- Coats metal parts to prevent oxidation and corrosion.
- Conditions seals and gaskets to prevent leaks.
It really is crucial to keep transmission fluid clean and full, or any of these functions could be compromised.
What Does The Transmission Fluid Do?
Its main function is to lubricate the transmission system. The lubrication helps with transferring the engine power to the ground.
The torque converter also uses the fluid to transfer rotation force from the engine to the transmission. The fluid also absorbs the heat created inside the system and dispenses it through the radiator.
Driving on low transmission fluid is extremely dangerous because it could lead to transmission failure and other costly repairs.
You should know what happens if your transmission fluid is low and take action immediately when the symptoms occur.
What causes low transmission fluid?
Gasket failures and tiny cracks or punctures in the transmission oil pan are the two most common reasons for low transmission fluid. Though there are certainly other faults that could leave you with low levels.
The leak has to be tangible, as transmissions are sealed systems, and there’s nothing to burn up, burn away, or be consumed.
#1. Gasket Failure or Bad Pan Seals.
Time, heat, and general wear-and-tear can cause the gaskets or pan seals on your transmission’s oil pan to fail, resulting in a slow leak.
These leaks are generally easy to spot. They’ll leave tiny puddles in your garage or parking space. If you crawl under the car, you should be able to spot leaks on the side of the transmission oil pan.
#2. A Crack or Puncture in the Transmission Oil Pan.
Cracks and punctures in the transmission oil pan are another very common type of transmission leak.
They are usually caused by running over something on the highway, taking the car off-road, and striking a rock or big tree branch. It’s also possible for a bad rust spot on an older car to leak fluid directly from the pan.
The size of the crack or puncture will determine just how fast you lose transmission fluid. This is usually even easier to spot than bad pan gaskets, as the leak will come straight out of the pan. A bad puncture might even leave you without any transmission fluid overnight.
#3. A Cracked Transmission Case.
Bad U-joints, cracks in the axle seals, and other faults that put excess torsion force on the transmission can crack the transfer case.
This crack can then let fluid leak out. Just how much comes out depends on the size of the crack. You’ll usually see it toward the rear of the transmission.
If you see a crack in the housing, you must stop driving it immediately. The more torsion stress you put on the housing, the more likely the crack will spread until the entire housing fails.
#4. Cracked or Punctured Transmission Fluid Lines.
A crack or puncture in one of the transmission fluid lines leading to the radiator is also one of the more common reasons for low transmission fluid.
These lines carry hot transmission fluid to the radiator to be cooled and then returned to the transmission housing. If a rock or road debris makes contact with either of these lines, fluid can leak out.
This is often a double-whammy as the fluid level goes down; it does a worse-and-worse job of cooling the transmission. Then friction builds up between the gears causing the remaining fluid to overheat and lose some of its lubricating properties.
Even if you can’t immediately spot the leak in the lines, you’ll still be able to see the drops of fluid under the car. Sometimes the small crack will let transmission fluid run along the damaged line dripping off just before reaching the radiator.
#5. A Bad Torque Converter.
A crack in the torque converter’s body can create a serious leak allowing transmission fluid to leak out. This usually starts out as a fault with the torque converter’s needle bearings.
When this happens, the car will increasingly have difficulty shifting gears. This is due to both low transmission fluid and the torque converter acts like a pump helping to move transmission fluid throughout the system.
When a torque converter house is damaged, you might get intermittent spraying of transmission fluid out of the crack.
You’ll likely also get a check engine or a check transmission light, as the TCM and the Valve Body won’t have the accurate fluid pressure they need to make the transmission respond to the engine’s power.
If it’s a bad torque converter seal, and the torque converter itself is fine, you’ll see a lot of transmission fluid in the bell housing. This is probably your “Best Case Scenario.”
#6. A Crack in the Axle Seals.
If an axle seal is cracked with age or damaged by contact with road debris, transmission fluid can escape from the transfer case.
This can be a little hard to spot at first, as the fluid leak is the most pronounced when you’re driving. Then when you get home, the drips stop, and you might not even have any transmission fluid spots on the pavement.
If you’ve looked everywhere else for the source of an axle seal leak and you’re still left scratching your head, you should turn your attention to the axle seals. If you feel carefully around the seal, you might find a wet spot where the fluid leaks out while driving.
Also, check the back side of the tires. Sometimes a small crack in the axle seal will let a tiny amount of fluid out, which then runs down the exterior of the seal until it meets the tire.
In such a case, the back of the tire will have a glistening red smear of transmission fluid and road grime. You might also notice smoke coming from your brakes if the transmission fluid makes it from the tire’s outside to the rotor’s interior surface.
Signs of low transmission fluid
Transmission fluid does not need to be changed during the entire lifespan of a vehicle. However, depending on the car you are driving, you may require to flush it a few times or change it after every 50,000 miles.
The low level of fluid could be the result of it leaking through a cracked or worn-out component. In that case, you have to fix the damaged part and refill the fluid.
How to tell if transmission fluid is low? Watch out for these low transmission fluid symptoms.
#1. Trouble Shifting Gears.
The first sign when your car is encountering a transmission fluid low is gear-shifting troubles. Dirt or gunk in the fluid is the primary reason for having a sluggish response from the transmission.
No matter whether you drive a manual or automatic, the oil in the gearbox has to be clean, and free of any dirt residue so that it can flow inside the parts without any snag.
Dirty oil will draw a too-slow response from the gear shifting. Low manual transmission fluid symptoms will make the changing of gears extremely difficult.
#2. Erratic Shifts.
Erratic shifts cause the shifting of gear to happen too late or too soon. It is one of the signs of low transmission fluid automatic cars. You could be sure of the problem if there is an accompanying banging sound.
The hydraulic pressure has to be precise and work smoothly for changing the gears in an automatic transmission. A lack of fluid will disrupt the rhythm of the shifting’s timing.
#3. Surging Transmission.
The condition causes a vehicle to lurch forward before falling backward during regular driving operations. The inadequate force from the fluid is the only reason for such surging movements.
#4. Delayed Gear Engagement.
The gear stick will produce a delayed response when you move it to the ‘Drive’ or ‘Reverse’ mode. A low level of fluid means low pressure in the transmission, which causes a delay in the gear change.
The response time is around 2 to 3 seconds, which is enough to tell you that there is something wrong with the transmission fluid.
#5. Gear Slippage.
Low transmission fluid symptoms also include the slipping of the engaged gear. It does not let the gear stay in the mode you have selected.
If the fluid level is right, the culprit must be the residue buildup that impedes the fluid to flow freely.
#6. Transmission Becomes Overheated.
One most important function of the fluid is to keep the transmission temperature at the normal level.
When there is not enough fluid to lubricate the components, there will be a huge amount of friction, leading to the production of excessive heat.
You will experience an overheated transmission in case of delayed shifts, gear slippage, power loss, or other related problems as some signs transmission fluid is low.
When you face any symptoms of low transmission fluid, pull off the car immediately to allow the components to blow off the steam. When the temperature is back to normal, try to drive to a servicing shop.
Call a towing service if the symptoms continue. Remember that the transmission system will suffer serious damage in case the temperature arises over 240°F.
#7. Noises.
If your transmission is in good operating order, you should not hear any noises when driving since it should shift smoothly. Unusual noises vary not just across manufacturers and models, but also between transmission types.
When you shift gears, manual gearboxes frequently create a loud clunking or grinding noise, whereas automated transmissions whine or hum.
Noises might suggest that the fluid level is low, but you won’t be able to detect the problem on your own. To avoid labor-intensive repairs because of the low transmission fluid sound, get the problem checked out by a professional expert as soon as possible.
#8. Burning Smells.
Any bad odor emanating from your vehicle should guide you to the nearest servicing center.
There are various reasons why your automobile may begin to emit a burning odor, one of which is the presence of overheated transmission fluid. This symptom may indicate a low fluid level.
When a gearbox becomes too hot, the friction between the components increases, causing much to build up and damage the transmission. If kept in this state, the transmission will eventually harm itself and become non-functional.
#9. Accelerating Slowly.
If your car is slow to start or unresponsive when accelerating from a standstill, it might be due to a gearbox problem.
If you notice that maybe you are driving on low transmission fluid with these above symptoms, take your car to the trusted local service shop and have it inspected and serviced right away.
#10. The Warning Light is On.
When a Check Engine light appears on your dashboard, you should always take it to a repair shop to have it checked.
This light might appear for a variety of reasons, one of which being a problem with your transmission fluid.
How to fix low transmission fluid?
The first step to fixing low transmission fluid is to check the fluid levels using the dipstick. “The transmission dipstick looks like the oil dipstick and has an orange or yellow handle”.
For those vehicles that don’t use dip-sticks, you will need to check your car’s manual or manufacturer’s website for more instructions.
The process is simple enough to be performed by a beginner and will take you around twenty minutes to two hours.
If this is your first time checking the fluid levels, then you will need mechanical gloves and maybe safety glasses for protection. The required tools include a funnel, a towel, and your car’s recommended transmission fluid. Here are the steps to follow:
- Pack on a flat-level surface and start your car to warm the transmission. Look at your vehicle’s manual to make sure that the car is in Park or Neutral depending on the set standard.
- Open the hood to locate the dipstick. Take it out and clean it off using the towel you have. We do this to ensure there is no oil on the stick when we measure the fluid levels. This helps provide a more accurate measurement.
- After cleaning it, place it back into its previous location and remove it once more. Take a look at the fluid level indicators. There should be two of them; one for hot and another for cold temperatures. Depending on the weather, the fluid level should not be lower than the relevant indicator.
- If the dipstick shows low fluid, then the transmission system leaks. Proceed to use the above signs to diagnose your problem.
- After finding what the issue is, take it to a mechanic or fix it yourself if it is not severe. Proceed to get your car’s specific transmission fluid and use a funnel to refill the system via the filler tube.
FAQs.
Q: What happens when the transmission fluid is low?
Having low levels of the transmission fluid in your system will cause your gears to miss when engaging them. Moreover, it will cause a grinding sensation when shifting through gears. The resultant effect may lead your car to shake, Jerk, and make clunking noises.
Q: Will the check engine light come on if the transmission fluid is low?
A check engine light may turn on in some vehicles but won’t in others. This comes down to two factors; the type of car you own and the severity of the damage caused by low transmission fluid.
A few high-end cars have separate controllers that will set a code when the transmission fluid is low.
Most vehicles will not set a check engine light on due to this fact. Low-end vehicles and a majority of others will only set the check engine light if other components in the car have been afflicted due to low transmission fluid.
Q: Can low transmission fluid cause jerk?
A good amount of transmission fluid in the system helps your car run smoothly when you shift or engage the gears. Low transmission fluid signs will make it hard to operate the gears, causing the car to jerk and lurch suddenly.
Q: Where do you add transmission fluid?
With your car’s specific transmission fluid in hand, take a funnel and put it in the opening from which you removed the dipstick gauge.
Add the transmission fluid little at a time while checking the fluid levels with the dipstick. This is to prevent you from overfilling the system. Proceed till the right levels are reached, return the dipstick, and you are done.
Final words
Diagnosing and fixing low transmission fluid problems is a vital skill that every car owner should own. Considering that your transmission will always tell you it’s struggling before it fails, you should have no problem addressing this issue.