How to Pick the Right Jeep JK Rear Differential Fluid
To find the correct differential fluid for your Jeep JK, you’ll need to know your rear axle type. You can easily change the fluid yourself.
Written by Rachel Rigolino
Reviewed by Melanie Reiff
The type of differential fluid that a Jeep JK takes depends upon its axle type. For 2018-2021 Jeep Wranglers with an M220 rear differential axle, you’ll use 75W-85 GL-5. If you have a Jeep JK with an M200 DRZ axle, 75W-140 GL-5 is recommended.
Nothing says “rugged” more than a Jeep Wrangler! The Wrangler JK is actually the third generation of this beloved off-road SUV, and it was manufactured between 2006-2018. JK owners love their vehicle’s ability to be just at home in a suburban parking lot as in a mountain forest clearing.
If you’re a Jeep owner who is intent on keeping their Wrangler JK in top running condition, then this guide—prepared by
Jerry
, the go-to comparison app for car insurance
—is meant for you! We’ll cover how to find the right rear differential fluid, how to change it, and when you might want to take your ride to a mechanic. For good measure, we'll also let you know how you can trim down your Jeep JK insurance costs.The best Jeep JK rear differential fluid
Jeep JKs do not all take the same differential fluid because their rear axles are not all the same. Here are some of the variations you may find:
Axle type | Differential fluid type |
|---|---|
M220 / DRE or DRF / (AKA Dana 35) | 75W-85 GL-5 |
M200 / DRZ (AKA Dana 35) | 75W-140 GL-5 |
Dana 44 | 80W-90 GL-5 |
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4.7/5 rating on the App Store | Trusted by 5+ million customers and 7 million cars4.7/5 app rating | Trusted by 5M+ driversThe different recommendations for the Dana 35 axle depend on whether you tow a lot—if you do, the 75W-140 is recommended. However, differences can also be due to the year of your Wrangler, so be sure to consult your owner’s manual.
If all of those letters and numbers seem confusing, they really just stand for different parts of the fluid. Here’s the common shorthand:
Abbreviation | Meaning |
|---|---|
SAE | Society of Automotive Engineers |
80W-90 | “W” indicates Winter–this means the differential fluid will work in low temps. |
API | American Petroleum Institute |
GL-5 | This number indicates how much sulfur-based modifier is in the fluid, which can be very important. |
What is rear differential fluid—and why does your Jeep need it?
If your Jeep JK has a rear differential, it means you have four-wheel drive (4WD). Power is directed to the wheels on the rear axle by the rear differential, which also helps your Jeep Wrangler JK to negotiate turns smoothly.
Differential fluid keeps your Wrangler’s differential from overheating and protects the gears/bearings in the differential from corrosion. If you don’t have enough fluid—or the fluid has lost its velocity (and thus its effectiveness)—the differential could overheat and no longer function properly.
Differential fluid is sometimes called gear oil, and some owners may confuse gear oil with engine oil—but these are not the same.
Here’s how differential fluid (gear oil) differs from engine (motor) oil:
- Differential fluid is thicker
- The additives in engine oil are different from those in differential fluid
- Corrosion is a problem in rear differentials, and differential oil is designed to combat corrosion
- While differential fluid can go longer between changes, the oil in engines must be changed every 3,000-5,000+ miles
How often to change Jeep JK rear differential fluid
Jeep experts recommend that you change differential fluids every 30,000–50,000 miles.
If you notice any of the problems below, take your Jeep to a mechanic. These are all symptoms of low/bad differential fluid, but they can also signal other issues with your JK:
- A burning smell from the rear axle region
- Unexpected noises (often howling) coming from the rear of your Wrangler
- Unusual vibrations from the rear of your Wrangler JK
MORE: Jeep resale value
How to change your Jeep’s differential fluid
Jeep owners are often relieved to discover that changing differential fluid is fairly easy. That is, if you have some mechanical know-how and you have the right tools (and the DIY bug), you should be able to handle this SUV maintenance yourself. If that's the case for you, you might be able to enjoy saving on
differential fluid replacement costs
.The following is a list of tools you’ll need for changing your differential fluid:
- About a gallon of differential fluid (consult your owner’s manual for grade/type)
- Additive (if required)
- Wheel chocks
- A socket wrench with extension
- Torque wrench
- Fluid transfer pump
- Drain pan
- Replacement drain plug and fill plug washers
Step 1: Find the right rear differential fluid for a Jeep JK. Be sure to choose the correct grade as indicated in your owner’s manual.
Step 2: Secure your Wrangler so that it will not roll with wheel chocks. You shouldn’t need to jack up your Wrangler JK in order to change the differential fluid.
Step 3: Locate and remove the fill plug; this will help the old fluid to drain.
Step 4: After you’ve located the drain plug, place your drain pan under this part of the differential.
Step 5: Remove the drain plug; allow the old differential fluid to drain.
Step 6: After you have put in the new differential fluid, replace the drain and fill plugs and use the new washers.
Step 7: Clean off any excess fluid.
If you’d rather have your differential fluid changed professionally, expect to pay between $70 to $150.
How to find affordable Jeep insurance
Finding the right rear differential fluid for a Jeep JK takes some research, but it’s well worth it to keep your car running smoothly.
Another thing that takes some research is finding the right
car insurance
policy—but this research often seems daunting. Luckily, comparison shopping for insurance is actually quite simple with
Jerry
, the super app for car owners—and it increases your odds on saving on your Jeep insurance costs. Begin by downloading the Jerry app or go to getjerry.com. In less than 45 seconds, Jerry collects all of your information from your existing insurance company. Next, you’ll be given quotes from top insurance companies. Find one you like, and Jerry takes care of the rest—securing your new policy and helping you cancel your old one. The average Jerry user saves up to $800+ a year on car insurance!
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