I changed the oil in our Eaton rear drive axle yesterday. This is an Eaton 23,000 lb. axle used on many motor homes. The owner’s manual says it should be changed every 250,000 miles, or 36 months whichever occurs first. I repaired the axle flange oil seal a few weeks ago and some of the oil leaked out. I thought I would just change all the oil instead of topping off.
The first issue was finding gear oil that meets the proper specs. The owner’s manual says to use synthetic gear oil meeting MIL-L-2105D specifications. This specification has been updated to MIL-L-2105E. I researched several synthetic gear oils and decided to use Redline #57904 75W90 GL5 gear oil. This gear oil is recommended for API GL-5, GL-6, MT-1, MIL-L-2105E, SAE J2360 and Chrysler spec MS-9763. I’ve used Red Line before and had good results. The owner’s manual says it takes up to 15 quarts.
I found Red Line 57904 on Amazon in both 1 quart and 12 quart cases.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
I raised the chassis all the way up on the air bags and then placed jack stands under the vertical braces next to the engine. The drain plug is a ½” square internal drive (see first picture). A half inch ratchet with a short extension fits it. The filler plug is a ½” external square, so I used a Crescent wrench. I used a large drain pan to catch the almost 4 gallons of gear oil. I removed the drain plug and left the filler plug in. This way you can test the air vent. You will hear it hissing as the oil drains. I let it drain overnight.
You need to clean the magnetic drain plug as it will have a fair amount of debris on it. The owner’s manual says to test the magnet and it should lift a 1½ lb weight. Reinsert it and torque to 35-50 ft. Lbs. Then remove the filler plug. Ours was very tight and it took both feet to loosen it. I had purchased an oil pump but didn’t use it. The filler hole is large enough so the Red Line oil bottles fit inside. You can only get about ¾ of the oil out of each bottle so you set one empty bottle aside and combine the remaining oil from three bottles into it. You repeat this until the differential is full. Ours took 14 quarts.
The manual is also very specific that you fill it up to the bottom of the filler, not just below. This is so the axle bearings get sufficient oil. The entire process takes only about an hour and could be quicker the second time around.
Hope this helps.
Linear Mode
