Posted by Traveler on April 13, 01 at 07:15:47:
In Reply to: Kluning Sound In Rear of Truck posted by jojo on April 12, 01 at 14:53:07:
Sounds like the transfer case clunk that is cured by the switch to the AutoTrak II blue fluid, PN 12378508.
"My inquiry response from GM:
Thank you for visiting the GM Goodwrench Service Plus website.
Both the red and blue fluid will work in your transfer case. I have
included a bulletin regarding
the fluid color change that should explain the reason for the two
fluids:
Info - Improved Automatic Transfer Case Fluid #99-04-21-006
Improved Automatic Transfer Case Fluid
1999-2000 Cadillac Escalade
1998-2000 Chevrolet and GMC K/T 4-Wheel Drive Pickups and Utility
Models
1999-2000 Chevrolet and GMC L Van Models
1999-2000 Oldsmobile Bravada
with Active Transfer Case (RPOs NP4, NP8)
Effective with vehicle production in late June of 1999, all active
transfer cases on the above
listed vehicles have been filled with Autotrak® II fluid, P/N
12378508 (P/N 10953626 in Canada).
This fluid is a light blue color rather than the red color of the
previous fluids and is the next
generation Automatic Transfer Case Fluid. The fluid also contains a
better friction modifier.
On the models listed above, the active transfer cases should only be
serviced using P/N 12378508
(P/N 10953626 in Canada), even if the original fluid was the red
Autotrak® fluid. The previous fluid
and the new fluid can be mixed or topped off if necessary. The new
Autotrak® II fluid will be the
only available fluid once the supply of the old red Autotrak® fluid
is exhausted on units older than
stated above.
The Owner's Manuals and some service information will specify the
incorrect fluid due to printing
the information prior to the fluid change being introduced.
Thank you for your inquiry.
Regards,
Goodwrench Internet Response Team"