Transfer Case - Moan Noise
File In Section: 7 - TransmissionBulletin No.: 86-74-02
Date: September, 1998
Subject:
Moan Noise in Transfer Case
(Replace Transfer Case Fluid)
Models:
1998 Chevrolet and GMC K1-2 Models with NV246 Transfer Case (RPO NP8)
1998 Oldsmobile Bravada
with NV136 Transfer Case (RPO NP4)
Condition
Some owners may comment about a moan type noise when the vehicle is operated in the AUTO 4WD position and is driven in deep sand, deep snow, or deep mud.
When operating K model vehicles in the above conditions, selecting the 4L0 or the 4HI position, instead of the AUTO 4WD, may help to reduce noise.
Cause
Condition may be caused by a slip-stick condition in the clutch assembly.
Correction
Drain the transfer case fluid. Add revised transfer case fluid using the part number listed below. Refer to the Service Procedure in Section 4-Transfer Case of the appropriate Service Manual. Refer to Corporate Bulletin Number 76-74-03, dated April, 1998, for information on removing the transfer case drain and fill plugs.
Parts Information
P/N Description Qty
12378396 Transfer Case Fluid 2
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use:
Labor Labor
Operation Description Time
K4290 Plug, Transfer Case Drain - 0.5 hr
Replace