Axle Lubricant Level Checking

s2 m 35.01.000

Notice: Failure to keep the rear axle filled to the proper level with the recommended lubricant can result in rear axle damage.

  1. Park the vehicle on a level surface, shut down the engine, and set the parking brake. Chock the tires.
  2. If the vehicle has just been driven, allow a few minutes for the lubricant to settle.
  3. Clean the fill plug and the area surrounding the fill plug on the side of the axle carrier. Remove the plug. Check lubricant level when the axle is cold, or near room temperature. See Fig.Component Locations, Detroit Axles and see Fig.Component Locations, Meritor Axles.
  4. Check that the lubricant is level with the bottom of the fill hole. See Fig.Axle Lubricant Level Inspection. If low, check for oil leaks, and correct as needed. Add oil to the level of the fill plug, using the lubricant, see Table.Detroit Drive Axle Lubricants for Detroit axles or see Table.Drive Axle Recommended Lubricant, Meritor Axles for Meritor axles.

    Note: Some Meritor axles have a small tapped and plugged hole located below the housing oil fill hole. This smaller hole is for the lubricant temperature sensor only and must not be used as a fill or level hole.

  5. Install the oil fill plug and tighten it 30 lbf·ft (41 N·m) for Detroit axles or 35 lbf·ft (47 N·m) for Meritor axles.

    Important:  A lubricant level close enough to be seen or touched is not sufficient. It must be level with the bottom of the fill hole.

  6. Check the axle housing breather. Make sure that it is open and unclogged. If the breather is plugged or damaged, clean or replace it as needed.

    Important: Always check the axle breather whenever checking the lubricant level. Check the breather more frequently under adverse operating conditions.

    Component Locations, Detroit Axles

    • Front View

    • Rear View

    1. Breather Hose

    2. Axle Housing Breather

    3. Oil Drain Plug

    4. Oil Fill Plug

    Component Locations, Meritor Axles

    1. Axle Housing Breather

    2. Oil Fill Plug

    Axle Lubricant Level Inspection

    • Correct (lube level at bottom of fill hole)

    • Incorrect (lube level below fill hole)

    Detroit Drive Axle Lubricants

    Detroit Drive Axle Lubricants*

    Important: Lubricant used in Detroit rear axles must meet Mercedes-Benz specification 235.20 (mineral) or 235.8 (synthetic). Mobil Delvac™ Gear Oil A 80W-90 and Mobilube™ HD-A Plus 80W-90 meet specification 235.20. Mobil Delvac 1 Gear Oil 75W-90 and Mobilube 1 SHC 75W-90 meet specification 235.8.

    Type

    Ambient Temperature

    SAE Viscosity Grade

    Mineral Oil

    –15°F (–26.1°C) and up†

    80W–90

    Synthetic Oil

    –40°F (–40°C) and up†

    75W–90

    *  Detroit rear axles do not require the use of friction modifiers.

    †  There is no upper limit on the ambient temperature.

    Drive Axle Recommended Lubricant, Meritor Axles

    Drive Axle Recommended Lubricant, Meritor Axles

    Recommended Lubricant Type

    Ambient Temperature

    Lubricant SAE Viscosity Grade

    Hypoid Gear Oil API Service Classification GL–5

    10°F (–12.2°C) and up*

    85W–140

    –15°F (–26.1°C) and up*

    80W–90

    –40°F (–40°C) and up*

    75W–90

    –40°F (–40°C) to 35°F (2°C)

    75W

    –40°F (–40°C) and up*

    75W–140

    Synthetic Gear Oil

    –40°F (–40°C) and up*

    75W–90

    –40°F (–40°C) and up*

    75W–140

    *  There is no upper limit on the ambient temperature.

Parent topic: Rear Axle