GM Service Manual Online
For 1990-2009 cars only

Info - Discontinue Flushing and Replacing Transfer Case Fluid Due to Bump/Clunk Concern

Subject:Discontinue Flushing and Replacing Transfer Case Fluid Due to Bump/Clunk Concern

Models:1998-2000 Chevrolet and GMC K1-2 Pickup and Full-Size Utility Models
1999-2000 Cadillac Escalade
with NP246 Automatic Transfer Case (RPO NP8)



This bulletin is being issued to cancel Corporate Bulletin Number 99-04-21-004. Please discard Corporate Bulletin Number 99-04-21-004 (Section 04 - Driveline/Axle).


This bulletin is being issued to advise dealerships to no longer flush and replace the transfer case fluid when a customer comments about a "bump" feeling when the vehicle accelerates from a stop.

When Corporate Bulletin Number 99-04-21-004 was issued, a new transfer case fluid had just been developed to correct this condition. Currently, a nickel-plated slip yoke is being developed that will correct this condition. A new bulletin will be issued as soon as parts are available.

Please share the information in this bulletin with customers who may inquire about this condition.