Checking the Axle Lubricant Level

sb mm 35.02.001

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

Note: If the vehicle is exposed to water deep enough to cover the hubs, disassemble and inspect them for water damage and/or contamination. See  of the Shuttle Bus Chassis Workshop Manual for instructions, or take the vehicle to an authorized Freightliner dealer.

  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. for a Detroit axle, or see  or see Fig. for a Meritor axle.

    4. Note: Some axles have a small tapped and plugged hole located near and 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.

  4. Check that the lubricant is level with the bottom of the fill hole. See Fig.. If low, check for oil leaks, and correct as needed. Add oil to the level of the fill plug. For a Detroit axle, use a lubricant recommended in Table..
    For a Meritor axle, add Castrol TranSynd synthetic automatic transmission oil.

    5. 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.

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

    Note: Engine-front configuration shown; engine-rear configuration is similar.

    • Front View

    • Rear View

    1. Breather Hose

    2. Axle Housing Breather

    3. Oil Drain Plug

    4. Oil Fill Plug

    Fig. 1, Component Locations, Detroit Axles

    1. Ratio Tag

    2. Drain Plug

    3. Limited Slip Lubrication Tag

    4. Filler Plug

    5. Model Number

    6. Axle Housing Breather

    7. Manufacturing Date

    8. Part Number

    Fig. 2, Meritor Rear Axle Differential, MB Shuttle Bus

    1. Axle Housing Breather

    2. Fill Plug

    3. Temperature Indicator Plug

    Fig. 3, Meritor Axle Housing (typical), XB Shuttle Bus

    • Correct (lube level at bottom of fill hole)

    • Incorrect (lube level below fill hole)

    Fig. 4, Axle Lubricant Level Inspection

    Table 1, Detroit Drive Axle Lubricants

    Detroit Drive Axle Lubricants 1

    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 up2

    80W–90

    Synthetic Oil

    –40°F (–40°C) and up There is no upper limit on the ambient temperature.

    75W–90

    1. Detroit rear axles do not require the use of friction modifiers.
    2. There is no upper limit on the ambient temperature.

    Table 1, Detroit Drive Axle Lubricants

Note:
Parent topic: Rear Axle
Document Number: 0000120562
Manual Publication Date: 2025-01-08
Topic Publication Date: 2024-11-18