Detroit® Model 4 and Model 6

49X mm 35.02.001

For all axles, including tandem drive axles and two-speed axles, perform the applicable procedures under the heading, ‘All Axle Models.’ For a two-speed axle with a shift unit, also check the shift unit lubricant; see under the heading, ‘Two-Speed Axles With Shift Unit.’

    Note: 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.

    4. Note: Some Detroit axles have a small tapped and plugged hole near and below the housing oil fill hole. This smaller hole is for a lubricant temperature indicator only, and should 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, using the lubricant recommended in Table..

    • Correct (lube level at bottom of fill hole)

    • Incorrect (lube level below fill hole)

    Fig. 1,  Axle Lubricant Level Inspection

    Table 1, New Final Drive Oil Capacity, New Final Drive

    New Final Drive Oil Capacity, New Final Drive
    Axle Type Oil in Hubs (2) Oil in Axle

    NFD Model 4 Forward Axle TP

    1.8 L

    9 L

    NFD Model 4 Rear Rear Axle TP

    1.8 L

    7.5 L

    NFD Model 4 Forward Axle SP

    1.8 L

    14 L

    NFD Model 4 Rear Rear Axle SP

    1.8 L

    11 L

    NFD Model 6 TP

    1.8 L

    9.5 L

    NFD Model 6 SP

    1.8 L

    11 L

      Table 1, New Final Drive Oil Capacity, New Final Drive

      1. 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.

    1. Install and tighten the fill plug 30 lbf·ft (41 N·m).

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

    2. Check the axle housing breather (see Fig. ). Make sure that it is open and unclogged. If the breather is plugged or damaged, clean or replace it as needed.

      • Front View

      • Rear View

      1. Axle Breather

      2. Breather Hose

      3. Temperature Sensor Port

      4. Oil Fill Plug

      Fig. 2, Detroit Model 4 and Model 6 Tandem Axle (forward axle shown)

    Note:
    Parent topic: Axle Breather and Axle Lubricant Level Inspection
    Document Number: 0000119489
    Manual Publication Date: 2024-05-16
    Topic Publication Date: 2024-10-31