How to Change Your Transmission Fluid

Car owners must frequently check their trucks to ensure they’re in tip-top condition. One of these regular maintenance checklists is to change the transmission fluid. Learn how to drain the oil, replace the filter and refill the transmission pan with fresh lubricant. 

What Is the Basic Function of the Transmission?

Before you roll up your sleeves for some messy work, it’s essential to understand transmission since it’s tied to the meat of the topic. 

What Is the Transmission and How Does It Work?

Your car’s transmission is the gearbox, which directs the engine’s power to the wheels to move the vehicle. This system also slows the engine down and makes the wheels run at different speeds.

The transmission consists of gears, allowing you to control the power delivered to the car under various driving conditions. It can be either manual or automatic. 

The automatic transmission gives drivers more freedom behind the wheel since they don’t have to worry about switching gears. The catch is it consumes plenty of gas, making it less fuel-efficient. On the other hand, the manual type allows for more control of the automobile. For instance, you can slow down instead of braking. The caveat is you may need weeks of maneuvering practice before you feel comfortable taking the car off the road. 

Without this automatic or manual engine moderator, the car will overheat and spin out of control. 

Where Is the Transmission Located?  

There’s no permanent location for the transmission since its spot depends on the make and model. It can either be in the front, middle or rear. The gearbox is often attached to the engine. In front-wheel-drive cars, it’s usually mounted within the compartment directly connected to the engine. In rear wheel-drive vehicles, it’s attached to the end of the engine under a housing. 

Your car’s manual is a good reference for checking the exact location of the transmission system. 

How to Tell if Transmission Is Bad or Faulty 

The signs of wear and tear on this part are due to many factors. For example, issues with the fluid often result in damaged transmission. You should be wary and proactive in addressing these problems. Failure to repair or replace a malfunctioning gearbox can put your safety at risk. Here are some indications:

1. Burning Smell

 If you feel a nasty sting in your nose coming from the car  — like melting plastic — it could mean the gearbox is overheating or the fluid is burning. It’s risky because it can cause electric fire. If you don’t know how to troubleshoot a car, contact a mechanic for a vehicle health checkup.

2. Leaking Fluid

The transmission fluid is one of many oils in your car. It has a sweet scent and red color to distinguish it from other lubricants. Checking if your vehicle is leaking fluid is simple. Look for any signs of oil on the garage floor or driveway. Grease marks on the ground are an indication of damaged transmission. 

3. Trouble Switching Gears

The transmission has reached its limit if you need to put more effort in switching gears. Another hint is if the car slips between gears when driving. These malfunctions are hazardous and may increase your risk for accidents. Fix the problem immediately. 

4. Strange Noise When the Car Is Neutral

Your car’s transmission needs immediate inspection if you hear any whining, buzzing or humming sound when the clutch is in neutral.

5. Vibration or Shaking

Unsteadiness when switching automotive cogs is another warming sign of a failing part. Get a mechanic to check the transmission.  

A habitual inspection can help you identify problems right away. Learn how to do it yourself or visit a mechanic regularly for a car health assessment. 

How to Change Transmission Fluid by Yourself

Some gearbox issues are caused by its lubricant. Learn how to examine transmission fluid quality and replace it. 

What Is Transmission Fluid?

The car uses different oils to move the parts without being damaged by constant mechanical friction. The transmission fluid keeps automotive parts from rubbing against each other. It coats the components with grease to minimize the grinding of rough surfaces and ensure the engine runs steadily.

The transmission fluid also acts as a thermal exchanger, diverting heat away from the engine so it doesn’t seethe. An engine can combust at temperatures ranging from 2,000 degrees Fahrenheit to 4,500 degrees Fahrenheit. The gearbox oil serves as a coolant to prevent the components from deteriorating.

How to Check the Transmission Fluid

Many vehicles have a dipstick, which you can use to measure how much oil is left inside the gearbox pan. Some modern cars don’t have it, but if you do — follow these steps to check the oil volume. 

1. Open the hood and locate the dipstick. 
2. Once you find it, turn the engine on to warm the vehicle at an operating temperature. 
3. Put the gear in neutral or park with the brake on. 
4. Once the engine is sufficiently primed, pull out the dipstick. 
5. Check the color. It should be reddish. Here’s how to tell the fluid’s health based on color. 

• Bright red: The oil is new and in good condition — no need to take action. 
• Dark red: Schedule a fluid top-up in the future. 
• Brown: The oil has started to oxidate, so keep it in mind and load it up soon. 
• Black: The oil is severely contaminated. Replace the transmission fluid immediately.
• Pink or foamy: The transmission is damaged or the cooler is contaminated. Replace the cooler and flush the transmission fluid.   

6. After identifying its quality, touch the oil with your index finger and rub it against your thumb. If you feel any fine particles, the fluid is polluted and the filter is worn out. 
7. Wipe the dipstick clean with a lint-free fabric, then reinsert it into the tube. 
8. Pull it out again to confirm the reading. Every dipstick has a marker, indicating the proper oil level. Some have “hot” or “cold” labels, while others have L or H (low or high) and Min and Max (abbreviations for minimum and maximum.) 

If you can’t find the dipstick or your car doesn’t have one, refer to the owner’s or car service manuals. Other models have inspection plugs that require special procedures when checking or replenishing the transmission fluid. 

Results of the Oil Check

The transmission fluid inspection has three probable outcomes.

• You only need to fill up if the oil is low, looks reddish and smells OK. 
• You should drain and replace the oil if it looks dark and smells burnt.  
• You should change both the fluid and filter if it’s black and mixed with debris,    

Transmission Fluid Refill

The process to replenish a low-level gearbox oil is straightforward. Follow these steps. 

1. Remove the dipstick from the tube. 
2. Insert the long funnel. 
3. Once the funnel is secure, begin adding fluid slowly. Add a small amount at a time, ensuring not to overfill. 
4. Recheck the reading with the dipstick.
5. Repeat steps 4 and 5 until you get the right fluid volume. 

Transmission Fluid Change

The first step is learning how to drain transmission fluid. Emptying the pan can be messy, but other than this, the process is beginner-friendly. You can hire a mechanic to do the dirty work or do it yourself and save labor money. Begin by following these instructions. 

How to Drain the Transmission Fluid

You must first clear the pan with the contaminated fluid. 

Things you need:

• Gloves
• Goggles
• Jack stands
• Collection pan
• Ratchet
• Rags or paper towels

If you’re ready, here are things you must do. 

1. Get the vehicle in the air and use jack stands or ramps as supports to maintain their elevation.
2. Wear your gloves and goggles for protection.
3. Once ready, slide the collection container and get under the car to locate the transmission pan.  
4. Examine it. Some models have removable plugs in the center, which you can rotate in reverse to start draining. Others have bolts around them that you need to loosen up before you can pull the pans free. Determine how to extract the used fluid.
5. When you’ve done that, place the collection receptacle below the pan.
6. Slowly remove the plug or unscrew the drain bolts using a ratchet one at a time for a controlled spill.

Get a bigger collection pan to minimize the mess on your driveway or parking area. Alternatively, you can place a large tarp under it that will prevent floor spills. Use the rags to wipe any overflows on the floor. 

How to Change the Transmission Filter

Can you change the transmission fluid without replacing the filter? Yes. You can leave it if the oil quality is good. However, a good practice is to detach the filter to check for cracks or holes that can cause leakage. If it does have even a tiny slit, swap it with a new part.

Things you need:

• Ratchet
• New transmission filter

Make sure to get an identical replacement filter. Ask an auto mechanic for advice if you don’t know what type to get. After pulling out the transmission pan, follow these steps. 

1. Use a ratchet to remove the bolt securing the filter to the car. 
2. Get the new filter and lubricate the O-rings with some grease before pushing them into the tube. 
3. Once done, attach the new filter. Line the fittings into the holes and push them in before tightening the bolt. Make sure it’s not too tight to avoid damaging the part.

After swapping the filter, the next step is to reattach the transmission pan. Before doing so, wipe it clean with a degreaser and a paper towel or clean rag. Use a ratchet to put all the bolts back. You can begin replenishing the fluid afterward.

How to Add Transmission Fluid

This process is similar to how you refill the transmission fluid.

1. Remove the dipstick.
2. Insert the long funnel.
3. Pour in the brand-new transmission oil.
4. Reinsert the dipstick and check if it’s at the right level. Generally, you need about 4-6 quarts to fill the transmission pan. However, it also depends on the make and model. Check the owner’s manual for this information.  
5. Once done, reinsert the dipstick and lock the tube.

This concludes the steps for changing the transmission fluid. You can give the car a test drive to check the gear-shifting functions. 

How Often Should You Change the Transmission Fluid?

The owner’s manual typically recommends changing the transmission fluid between 30,000 and 100,000 miles, but regular inspection will ideally tell you when it’s time for a replacement. You may need to fill up the oil regularly if you’re constantly towing in hot weather. Frequent inspection and maintenance is crucial. If you detect foul smells and warning signs before your vehicle reaches 30,000 miles, resupply the oil. 

What Happens if You Don’t Change the Transmission Fluid?

Like engine oil, transmission fluid wears out and loses its lubricating and cleaning properties. It can cause excess friction and deteriorate the internal clutches when shifting gears. It can also lead to overheating issues. Degraded lubricant loses its ability to regulate combustion heat, damaging the bearings, gears and moving parts. 

How Much Does Changing the Transmission Fluid Cost?

The average cost of changing the transmission fluid is around $150 to $200, whereas a new filter often ranges from $100 to $250. Therefore, a transmission fluid and filter change can cost between $250 to $450. You can save a few bucks if you buy the parts and do the maintenance yourself.

How Much Does it Cost to Rebuild a Transmission?

If you still experience gear issues after restocking the fluid, the problem might be with the transmission. Schedule an inspection with a mechanic to pinpoint the underlying issue. 

On average, a transmission repair can cost between $1,800 and $3,400, depending on the damage to the parts. The labor typically starts from $500 to $1,200. 

If repair is impossible, a new transmission will cost $1,800 to $3,500.

Change Your Transmission Fluid Manually at Home

Owning a car involves several maintenance obligations that can quickly burn a hole in your pocket. Learning to do simple regular checks and repairs — like changing transmission fluid — can minimize associated expenses. Fortunately, you don’t have to be an automotive expert to learn a trick or two about vehicle maintenance. Follow the above steps to change transmission fluid in the most economical way.