Jeep Transmission Fluid Change: How To Do It?

Don’t ignore the transmission fluid in your Jeep. It may be the last thing on your maintenance list, but changing it is crucial to the proper function of the transmission system. So, here I am with a Jeep transmission fluid change article to show you how to do it.

I’ll take you step-by-step through this process, and I will also tell you the signs to look out for when your transmission fluid is due for a change.

So, are you ready to get under your Jeep? Let’s go, guys!

What Is The Transmission Fluid?

The transmission fluid is vital for both manual and automatic transmission systems. This fluid functions as a lubricant to protect the car’s clutch packs and gears against friction and overheating. It also allows for smooth and crisp shifting by enabling seamless engagement and disengagement of the gears. 

Functions Of The Transmission Fluid

Acts As A Hydraulic Fluid

When you want to shift the gears, the transmission fluid goes through a series of passages to engage the chosen gear. The fluid compresses plates in the clutch pack, connecting the engine to the transmission output shaft and directing power to the wheels. This process requires hydraulic fluid, which is the transmission fluid in this case.

Combats Heat

Transmission systems operate at high temperatures. The heat leads to the breaking down of the transmission fluid. This then causes varnish and sludge to clog up the system’s passages. It’s the work of the transmission fluid to fight heat and control the high temperature in the transmission system.

Protects Against Wear

Since the transmission fluid is a lubricant, it protects transmission components from wear caused by heat and metal-to-metal contact.

Why Do I Need To Change The Transmission Fluid?

The transmission fluid deteriorates over time through oxidation. It can also collect debris and sludge that inhibit it from performing as it should. Therefore, you need to change the transmission fluid according to Jeep’s maintenance schedule of 60,000 miles. This is recommended by the ZF company that made the 8-speed automatic transmission on Jeep vehicles.

Jeep vehicles with a manual transmission should have their transmission fluid changed every two years. That’s 30,000 miles for the NSG 370 manual transmission in the Jeep Wrangler. If your vehicle operates on low or contaminated transmission fluid, it can lead to catastrophic failure of the transmission components.

The Signs Your Jeep Needs To Change The Transmission Fluid

Your Jeep will have a few signs that indicate you need to change the transmission fluid. Here are the most common.

Delay In Acceleration

When you accelerate and hear the engine rev, your Jeep’s transmission may be stuck in gear, but you’re not going any faster. In Jeep’s manual transmission, there will be some resistance when shifting. This sign is directly related to low transmission fluid.

Slipping Gears

Dirty transmission fluid causes a lack of hydraulic power, causing the gears to slip. This happens because your Jeep’s transmission is not maintaining enough pressure to stay in gear. You may find that the vehicle can suddenly shift into a higher or lower gear when trying to keep your current speed. 

Grinding Noises

Dirty or low transmission fluid can cause grinding or unusual noises. These sounds come from metal-to-metal touching as these parts lose their lubrication. Usually, you’ll hear parts grinding into each other when you shift.

Puddles Under Your Car

While this symptom can indicate other issues such as leaking coolant, transmission fluid is red and smelly with an oily consistency. Hence, it is easy to distinguish from other fluids. Still, the transmission fluid changes into a darker color when it deteriorates, which is a good sign that you need to change it.

Can I Change It By Myself?

Yes, you can change the transmission fluid at home. Nonetheless, it’s a messy job that’s not for the faint-hearted. You will need to be fully prepared with the right tools and have enough time to complete the job.

How To Check Transmission Fluid

The first thing is to consult your Jeep’s manual for specific instructions about checking the transmission fluid. Most Jeeps come with a transmission fluid dipstick. If yours is one of them, here’s how to go about it.

• Park the vehicle on a flat surface
• Check the manual to see if you need to check the transmission fluid when the Jeep is running or not. You’ll need to be careful around hot components if your vehicle requires the engine to be running.
• Have the car in park and apply the parking brake before getting out of the vehicle.
• Identify the transmission dipstick in the engine compartment. It is usually brightly colored with a red or yellow T handle.
• Remove the dipstick by its handle. It is pretty long since it runs from the engine into the transmission pan. Get it out while being careful not to spill hot fluids on the hot engine or exhaust parts.
• Wipe the transmission dipstick with a rag and insert it into the tube. Ensure that it’s well-seated in the tube. Remove the dipstick and check the fluid level against the marks on it. You will see low, full, and overfull marks. 
• The ideal transmission fluid level is near the full mark. If you have a leak, the level will be low, so you’ll need to refill it and have the leak fixed as soon as possible.

How To Change The Transmission Fluid In Jeep (Step-by-Step Guide)

When it’s time to change the transmission fluid in your Jeep, you will need to prepare a few tools for the job. You’ll also need at least two hours of your time.

Tools

• New transmission filter for your Jeep
• A new bottle of transmission fluid 
• A new transmission pan gasket
• Large catch pan
• Rags
• Cardboard
• Funnel
• Scraper
• Torx bit and driver
• 3/8-inch drive ratchet and extensions
• 13mm or 15mm socket
• Aerosol cleaner
• Jacks and jack stand

How To

Step 1: Lift The Vehicle

Use jacks and a jack stand to lift your Jeep. While you can get under most Jeeps without the help of stands, it’s a good idea to have enough clearance to work.

Step 2: Drain The Automatic Transmission Fluid

Likely, your Jeep does not have a drain plug. This is because it was a source of leaks in earlier models. Nonetheless, if yours comes with a drain plug, remove the bolt and let the fluid drain into the catch pan. 

For Jeeps without a drain plug, you’ll have to loosen all the bolts on the pan but keep the bolts in one corner from falling. Place a catch pan, rags, and maybe cardboard under the transmission pan. Then, use a tool to gently pry on the pan to angle down to let the fluid drain.

Step 3: Remove The Transmission Pan

Remove the transmission dipstick first, then the remaining bolts, and slowly lower the transmission pan. It will have leftover fluid that can end up on your driveway or garage. Be careful not to break or bend any knobs on the driveshaft or exhaust components. 

Step 4: Clean The Transmission Pan

The transmission pan will be dirty, which is expected. What’s not normal is having pieces of clutch or chunks of metal in the pan. If so, it’s best to seek the help of a mechanic. Otherwise, you’ll find a small magnetic plate on the bottom. Clean the pan, and the magnet, then replace the magnet and set it aside.

Step 5: Replace The Filter

Your Jeep likely has a flat filter that bolts the transmission valve body. Remove the bolts using the Torx bit. Then, twist the filter around to release the rubber. Pull the filter down and clean the mounting surfaces using the aerosol cleaner.

Install the new filter and lube the gaskets, bushings, or O-rings with some transmission fluid. This will prevent components from being nicked as you insert the new filter. 

For a spin-on filter, you only need bare hands to install it. Still, a canister filter will require adding fluid so that it’s not running dry when you use it for the first time.

Step 6: Reinstall The Transmission Pan

Place a new transmission pan gasket on the pan. You may find that the bolt holes are smaller than the bolts so that they fit snugly with no chance of leaks. Hung the pan up using two bolts at the corners. Ensure that bolts are well-aligned before tightening them with a ratchet from side to side and then front to back. 

Torque the bolts to 15 ft/lbs to prevent the chance of a leak.

Step 7: Add Transmission Fluid

After reinstalling the pan, add four to five quarts of transmission fluid until it shows on the dipstick. Ensure not to overfill it because it will start to foam once it warms up.

And that’s how you change the transmission fluid in a Jeep.

All Jeep Generations Transmission Fluid Type

How Much Does It Cost To Change The Transmission Fluid In A Jeep?

The approximate cost of changing the transmission fluid in a Jeep Wrangler is $145 – $167. The labor costs usually rate between $84 and $106, and the parts cost $61. This cost will vary depending on your location and your Jeep’s model. 

Conclusion

That’s a wrap for now. A Jeep transmission fluid change is not a complicated task. You just require the right tools, and the job will be done in two hours at most. Changing your transmission fluid keeps the transmission system running perfectly, and it will help you get the most out of your Jeep.

Frequently Asked Questions (FAQs)

1. Which is better, transmission flush or change?

A transmission fluid change is better than a flush since you change the filter, whereas a flush does not warrant a filter change. Hence, any particles or sludge could back into the system through the filter and cause component damage.

2. Why should you never flush the transmission fluid?

Again, flushing the transmission fluid can dislodge debris and cause it to move inside the transmission system. In addition, the old fluid is pushed out using the new fluid, so it requires even more fluid to fill the flushing machine and the transmission line.

3. What happens if you never change your transmission fluid?

If you never change the transmission fluid, it will degrade and fill with grime and debris. As such, it will not lubricate the gears and the clutch pack. Moreover, it will not fight the heat, causing undue stress on the transmission system. 

4. Should I change transmission fluid after 100k miles?

Changing the transmission fluid after 100,000 miles is clear-cut advice from car owners. So, yes, if your Jeep is hitting the 100K mile mark on the odometer, it’s time you did a transmission change.

Yet, it’s better to follow your owner’s manual recommendation. Jeeps have different intervals ranging from 30,000 miles for manual transmissions to 60,000 miles for automatic transmissions.

5. Can you mix old and new transmission fluid?

No, it’s not a good practice to mix old and new transmission fluid. This is because you’ll still have sludge floating around. Moreover, the fluid won’t have the ideal viscosity, affecting the transmission system’s performance.

Read more: Service Shifter Jeep Cherokee: What Does It Mean and How to Fix It When Lighting?