Transfer Case Fluid Change

This procedure drains and refills the NV271 or NV273 transfer case fluid with fresh ATF+4 to maintain proper lubrication and operation.

Warnings

Tools required

Parts

• Transfer case drain plug washer × 1 — Use OEM specification
• Transfer case fill plug washer × 1 — Use OEM specification

Fluids

• ATF+4 — 2.5 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Place wheel chocks behind rear wheels
3. Allow transfer case to cool if vehicle was recently driven
4. Raise vehicle using jack and support securely on jack stands at frame rails
5. Ensure vehicle is level front-to-back for accurate fill procedure

Procedure

1. 1

   Locate transfer case plugs
   Position yourself under the vehicle behind the transmission. The transfer case is mounted directly behind the transmission. Locate the fill plug on the passenger side of the transfer case and the drain plug on the bottom of the case. Both plugs use a 3/8-inch square drive; a ratchet extension typically fits directly into the plug (verify against the service manual, as some units use a hex plug).
2. 2

   Remove fill plug first
   Using the 10mm hex socket, loosen and remove the fill plug from the passenger side of the transfer case. Removing the fill plug first ensures you can refill the case after draining. If the fill plug is seized or damaged, do not proceed with draining until it can be removed.
3. 3

   Position drain pan
   Place the drain pan directly beneath the transfer case drain plug on the bottom of the case. Position it slightly forward as fluid will flow forward initially.
4. 4

   Remove drain plug and drain fluid
   Using the 10mm hex socket, slowly loosen the drain plug. Once loose, quickly remove it by hand and allow the old ATF+4 to drain completely into the pan. This will take approximately 5-10 minutes. Inspect the drained fluid for metal particles or debris that may indicate internal wear.
   ⚠Fluid may be warm and will flow quickly once plug is fully removed.
5. 5

   Clean and inspect drain plug
   Clean the drain plug threads with a shop rag. Inspect the plug threads and sealing surface for damage. Remove and discard the old copper or aluminum crush washer from the drain plug. Install a new drain plug washer onto the plug.
6. 6

   Reinstall drain plug
   Thread the drain plug with new washer into the transfer case by hand to avoid cross-threading. Tighten the drain plug to specification using a torque wrench.
   Torque spec

   Transfer Case Drain Plug25 Nm (18 lb-ft)
7. 7

   Fill transfer case
   Using a fluid transfer pump or bottle with hose, insert the hose into the fill plug hole on the passenger side. Slowly pump ATF+4 into the transfer case. The case is full when fluid begins to drip or trickle out of the fill hole. Add approximately 1.7 to 2.0 quarts total (fill until fluid reaches the bottom of the fill hole). Allow a few moments for fluid to settle and top off if needed until fluid reaches the bottom of the fill hole threads.
8. 8

   Clean and install fill plug
   Clean the fill plug threads with a shop rag. Remove and discard the old crush washer. Install a new fill plug washer onto the plug. Thread the fill plug into the transfer case by hand, then tighten to specification using a torque wrench.
   Torque spec

   Transfer Case Fill Plug25 Nm (18 lb-ft)
9. 9

   Clean and inspect for leaks
   Wipe down the transfer case exterior around both plugs with a clean shop rag. Inspect both the drain and fill plugs for any signs of leakage around the threads or washers.
10. 10

    Lower vehicle
    Remove jack stands and carefully lower the vehicle to the ground. Remove wheel chocks.

Reassembly

1. Ensure both drain and fill plugs are torqued to specification with new crush washers installed
2. Verify no fluid leaks are present at either plug location

Verification

• Start the engine and shift the transfer case through all positions (2H, 4H, N, 4L) while stationary
• Allow vehicle to idle for 2-3 minutes, then shut off and recheck fluid level at fill plug - fluid should be at the bottom of the fill hole threads
• After first test drive, recheck both plugs for any signs of seepage or leakage
• Monitor for proper transfer case operation with no unusual noises or difficulty shifting between ranges

Related trouble codes on this vehicle

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