MD and HD Series

m2 mm 26.05.002

Notice: To prevent dirt from entering the transmission, use only clean containers and fillers for the transmission fluid. Do not use fillers or containers that have been used for water or antifreeze. Dirt, water, or antifreeze could damage the transmission.

Table 1, Approved Allison Transmission Lubricants

Approved Allison Transmission Lubricants

Lubricant Type1

Temperature: °F (°C)

 All Allison Transmissions 

Castrol TranSynd™ (synthetic)

Above –22 (–30)

Dexron® III

Above –13 (–25)
  1. Lubricants listed in order of preference. Do not mix types of oil.

Table 1, Approved Allison Transmission Lubricants

Table 2, Allison Transmission Lubricant Capacities

Allison Transmission Lubricant Capacities

Transmission Model

Fill Capacity:1 qt (L)

 On-Highway Transmissions 

1000/2000/2400 Series (standard sump)

15 (14)

1000/2000/2400 Series (shallow sump)

13 (12)

 HD/MD Series 

HD4060/4560 (standard sump)

36 (34)2

HD4060/4560 (shallow sump)

26 (25)2

MD3060/3066/3560 (standard sump)

19 (18)

MD3060/3066/3560 (shallow sump)

10.5 (10)
  1. Quantities listed are approximate. Add the recommended amount of fluid as listed under fill capacity, 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 2, Allison Transmission Lubricant Capacities

  1. Park the vehicle on a level surface and apply the parking brakes.
  2. Operate the vehicle until the transmission reaches normal operating temperature: 160 to 200°F (71 to 93°C).
  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. If only the filter is being changed, do not drain the fluid.
  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..

    1. Filter Cover

    2. Filter Element

    3. Filter Element O-Ring

    4. Square-Cut Seal

    Fig. 1, Allison MD and HD Series Transmission Filter Locations and Components

  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. Install a new drain plug O-ring, and install the drain plug. Tighten the drain plug 18 to 24 lbf·ft (25 to 32 N·m).
  13. Refill the transmission with fresh Dexron® transmission fluid (see Table.) and check the fluid level. See Table. for lubricant capacities.
  14. Check and adjust the fluid level using the appropriate Allison Transmission procedure in MOP Replacement and Inspection of the Air Cleaner Element.
Note:
Parent topic: Allison Transmission Fluid and Filter Changing
Document Number: 0000120830
Manual Publication Date: 2025-02-11
Topic Publication Date: 2024-11-06