K 1500 Truck 4WD V8-4.8L VIN V (1999)
Fluid Pan: Technical Service Bulletins
Transfer Case - Use of Heat to Remove Fill/Drain Plugs
File In Section: 04 - Driveline Axle
Bulletin No.: 99-04-21-001
Date: April, 1999
INFORMATION
Subject:
Use of Heat for Difficult to Remove Transfer Case Fill and Drain Plugs
Models:
1998-99 Chevrolet and GMC K1-2 Suburban, Utility Models
1998-99 Oldsmobile Bravada
with NV136/246 Transfer Case (RPOs NP4, NP8)
This bulletin is being revised to add the 99 model year and part Information. Please discard Corporate Bulletin Number 76-14-03 (Section
7-Transmission).
Some transfer case fill and drain plugs may be difficult to remove. In some cases, the plug may be "rounded out" attempting to remove the plug. These
plugs are made of aluminum and have a 1/4 inch square hole designed to receive a 1/4 inch square drive extension. Installation torque may have been too
high causing difficulty in removal.
Caution:
To help avoid a fire, thoroughly clean the area around the fill and drain plugs of grease build-up before heating and use only an electric heat gun. DO
NOT USE AN OPEN FLAME. If sources other than an electric heat gun are used, the transfer case may catch fire and cause personal injury.
In cases where the plugs cannot be loosened, the use of an electric heat gun may make plug removal possible. Heat should be applied to the case around
the plug, not directly on the plug, for one to two minutes. Use only enough heat to loosen the plug. Also, fully Insert the 1/4 inch square drive extension
onto the plug before turning the plug.
Important:
Do NOT use plugs made of steel or brass. These may cause a severe corrosive reaction when in contact with the magnesium case, making future
removal even more difficult.
If the fill and drain plugs are damaged during removal and must be replaced, use only aluminum replacement plugs. Replace the drain and fill plugs
(Internal, square drive tool access design) with the EXTERNAL HEX DESIGN plug, P/N 15032997. When you install the transfer case fill or drain
plug, tighten the plug to 20 N.m (15 lb ft).
Parts information
P/N
Description
Qty
15032997
Plug, Transfer
1
Case Oil Fill
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation
Description
Labor Time
Plug, Transfer
Use published
K4290
Case Drain -
labor
Replace
operation time
