Allison Transmission Fluid and Filter Change

cen mm 26.02.000

When draining transmission fluid, check for evidence of dirt or water contamination. A small amount of condensation will appear in the fluid during operation.

Water contamination is normally characterized as a milky discoloration of the transmission fluid. Obvious contamination of the transmission fluid indicates a leak between the water and fluid areas of the transmission cooler. Inspect and pressure-test the cooler to confirm the leak; replace leaking transmission coolers.

  1. Drain the transmission when the fluid is warm. If not already warm, run the engine until the transmission reaches normal operating temperature: 160 to 200°F (71 to 93°C).
  2. Park the vehicle on a level surface. Apply the parking brakes and chock the rear tires.
  3. Clean the area around the drain plug and the transmission fluid pan. Place a drain pan under the transmission and remove the drain plug. Examine the fluid as it drains.
  4. Remove the 12 mounting bolts (six each) from the two filter covers.

    5. Note: A lot of fluid will drain when the filter covers are removed.

  5. Remove the filter covers, O-rings, and two square-cut seals from the transmission. See Fig..
  6. Remove the filters from the bottom of the control module.
  7. Lubricate the new O-rings with transmission fluid, and install them on the cover assemblies.
  8. Install a new square-cut seal on each cover assembly, and install the fluid filter elements on the cover assemblies.
  9. Install the filter and cover assemblies into the filter compartment.
  10. Align each cover assembly with the holes in the channel plate sump, and push the cover assemblies in by hand to seat the seals.

    11. Notice: Do not use the bolts to draw the filter covers to the sump. This can damage the covers, seals, or sump.

  11. Install six bolts in each cover, and torque the bolts 38 to 44 lbf·ft (51 to 61 N·m).
  12. Replace the drain plug O-ring, and install the drain plug. Tighten the drain plug 18 to 24 lbf·ft (25 to 32 N·m).

    1. Filter Cover

    2. Filter Element

    3. Filter Element O-Ring

    4. Square-Cut Seal

    5. Drain Plug

    Fig. 1, Allison Transmission Filter Location and Components

  13. Refill the transmission with fresh automatic transmission fluid and check the fluid level. See Table. for transmission lubricant capacities, and Table. for approved transmission lubricants.

    Table 1, Allison Transmission Lubricant Capacities

    Allison Transmission Lubricant Capacities

    Transmission Model

    Refill Capacity 1: qt (L)

    HD4060/4560 (standard sump)

    36 (34) 2

    HD4060/4560 (shallow sump)

    26 (25)

    1. Quantities listed are approximate. Add listed amount of fluid, then perform a "hot check" and add fluid as needed. Do not overfill.
    2. Add 3 quarts (3 liters) if equipped with a PTO.

    Table 1, Allison Transmission Lubricant Capacities

    Table 2, Approved Automatic Transmission Lubricants

    Approved Automatic Transmission Lubricants

    Lubricant Type 1

    Temperature: °F (°C)

    All Allison Models

    Castrol TranSynd (synthetic)

    Above –22 (–30)

    Dexron® III

    Above –17 (–27)
    1. Lubricants listed in order of preference. Do not mix fluid types.

    Table 2, Approved Automatic Transmission Lubricants

Note:
Parent topic: Transmission
Document Number: 0000122003
Manual Publication Date: 2025-02-11
Topic Publication Date: 2024-06-04