How to Change the Differential Fluid in a 2003 Dodge Ram

The rear differential on your Dodge Ram pickup is filled with gear oil that lubricates and cools the gears and bearings inside the case. Changing the oil will help prevent any failures and minimize wear to those bearings and gears. There are several optional differentials available in the Dodge Ram and while the process for changing the oil is the same, the type of gear oil may differ, so be sure to check with the dealer to get the right oil for your truck.

Things You'll Need

• Floor jack
• Jack stands
• Oil drain pan
• Socket set
• Ratchet
• Clean rags
• Torque wrench

Instructions

1. Raise the rear of your Dodge truck with a floor jack under the rear differential. Position a set of jack stands under the axle tubes and lower the jack until the truck is secure on the jack stands.

2. Place a large oil drain pan under the center of the differential to catch the old oil, then loosen the bolts on the differential cover with a socket and ratchet. Remove all the bolts except the top one, then pry the bottom of the differential cover loose and allow the oil to start draining into the pan.

3. Remove the bolt from the top of the cover and remove the cover from the housing. Inspect the cover for damage, wiping it down with a clean rag so you can see if there is any damage to it. Use a gasket scraper to remove any old gaskets or material from the mounting surface of the cover.

4. Scrape the old gasket material off the mounting surface of the differential, then wipe out the differential housing with a clean rag. Look for any metal pieces or shavings that may indicate excessive wear or damage in the housing while you have the cover off.

5. Position the cover and a new gasket on the differential, install the retaining bolts, then tighten them with a socket and ratchet using a criss-cross pattern. Torque the cover bolts to 30 ft-lbs. with a torque wrench.

6. Remove the rubber fill plug on the differential cover, prying it out with flat screwdriver. Fill the differential with Dodge-approved gear oil until the oil starts to seep out of the top of the hole. Push the plug into the hole once the differential is full.

7. Raise the rear of the truck off the jack stands with a floor jack from under the differential. Remove the jack stands and lower the truck to the ground. Remove the jack from under the truck.

References

• "Dodge Ram Pickup Factory Service Manual"; The Chrylser Group; 2003