How do I change my differential fluids?
Routine inspections, fluid checks, and oil changes are key to maintaining the life of your Jeep and engine. While many people remember to change their engine oil, some tend forget to change out their differential fluids as well. This is a fairly easy task, but it does take a little longer compared to a normal engine oil change.
I am not going to go into specifics on how the gears work within the axle, but I will tell you about the importance of keeping them maintained. When the Jeep is in motion, the gears transfers power into the wheels to let them spin at different RPMs. The gears may reach a certain temperature that could possibly melt or warp the teeth of the ring and pinion, which may lead to serious damage. Over time, if the gear oil has not been changed contaminants tend to thicken up the oil causing it to be less effective for cooling and lubrication.
For starters, the purpose of the gear oil that goes into the differential is to help keep the gears and the differential unit cool. This job should done approximately every 30,000 to 60,000 miles. You may need to change the oil more frequently depending on the usage of your Jeep. If damage has occurred from the lack of maintenance in the differential then the cost to replace the parts including labor could be worth thousands.
Now let’s begin! P.S. the instructions were based off Jeep Wranglers 2014-2017 with stock axles.
What do I need?
- Oil Pan
- Brake Cleaner (2-3 cans preferred)
- Eye Protection
- RTV or Differential Seal/Gasket
- Gear Oil Manufacturer Suggested Grade
- Limited Slip Differential Oil (If not mixed in gear oil)
- 3/8″ Drive Ratchet
- 3/8″ Ratchet Extension
- 1/2″ Socket
- Soft Mallet
- Flat Tip Screwdriver, Razor Blade, or Scraper
Step 1: The Jeep should be parked with parking brakes engaged. The engine should be cooled down prior to work. Locate the differential (aka the pumpkin) on your axles.
Step 2: Place the oil pan directly underneath the differential. Proceed to drain the oil. There are two methods to doing this. The first method is to remove the bolts that attaches the cover to the axle using the 1/2″ socket (start from the bottom and work your way up) and leaving the top bolt on. Use a soft mallet, razor blade, or flat tip screwdriver to break the seal on the bottom of the cover. The second method is to drain the oil prior to removing the cover. To do this, locate the two plugs installed. One is the fill plug and the other is a drain plug. Both plugs should be removed for proper drainage using a 3/8′ ratchet and extension.
Note: As you can see above, the oil has either been contaminated or neglected from servicing.
Step 3: Once the oil has completed draining, remove the differential cover completely. There are different methods to removing the cover; use a mallet to tap it off, but be careful as you may damage components or use a flat tip screwdriver to pry it off.
Step 4: When the cover is removed and the gears are exposed, then cleaning and inspecting is the next step. You need to clean the excess RTV around the differential using a scraper or a flat tip screwdriver. Then you need to clean the inside. Most people prefer to use brake cleaner as it dries off fairly quick. Have a look around to see if there are any visible damage.
Step 5: After the gears, clean the cover. Then apply the new RTV or gasket on the cover and prepare to install.
Step 6: Install the cover using the factory bolts and 1/2″ socket and ratchet. Torque to spec. Also do not forget to install the drain plug as well.
Step 7: It’s time to fill the differential up with gear oil. Fill up the differential with the required amount.
For Jeep Wrangler JK:
Dana 30 Axle (2.1 Pints/1.0 Liters)
Dana 35 Axle (3.5 Pints/1.7 Liters)
Dana 44 Front Axle (2.7 Pints/1.3 Liters)
Dana 44 Rear Axle (4.75 Pints/2.25 Liters
Step 8: Once you have filled the differential with the proper amount of oil, install the fill plug and you are done! Steps apply to both the front and rear axle. Positions for plugs may vary.
After driving it a few miles check and sure the differential was sealed properly by looking for leaks or signs of oil.
If you have any questions, do not hesitate to ask!