HARSH SHIFTING CONDITIONS UPDATE/NEW CALIBRATION PKG.

TRANSMISSION APPLICATIONS: SUBJECT:

1990/1991 HYDRA-MATIC 3L30 (MD2) NEUTRAL TO DRIVE BUMP, HARSH 3-2 DOWNSHIFTS AND HARSH 2-3 LIFT FOOT (UPDATE CALIBRATION)

TRANSMISSION MODELS: VEHICLE APPLICATIONS: UL-D25, UL-D27, UL-D28,UL-D33 1990-91 CHEVROLET TRACKER, GMC TRACKER

Condition:

--------- Harsh 3-2 downshifts, 2-3 lift foots and harsh neutral to drive engagement.

Correction:

---------- New Calibration packages.

Date of Production Change:

Beginning with transmission serial number 3 771 582, on January 31, 1991, the new calibration number UL-D34 went into production to reduce the harsh shift conditions.

NOTE: Transmission Model: UL Transmission Calibration: DXX Both are located on transmission identification TAG. refer to Figure 1.

Service Parts Information: UL-D25, UL-D27, UL-D28 Models.

Service Package Number: 96040746-Package, Calibration Update

Package Contains: Low Speed DTV Spring (Pink/Brown) Servo Piston Assembly High Speed DTV Spring (Green/White) High Speed DTV Valve Transfer Plate Oil Pan Gasket Servo Cover Gasket Transfer Plate to Case Gasket Transfer Plate to Valve Body Gasket 12 Screw Washer Assemblies

Service Parts Information: UL-D33 Model

Service Package Number: 96040747-Package, Calibration Update

Package Contains: High Speed DTV Spring (Green/White) High Speed DTV Valve Transfer Plate Oil Pan Gasket Servo Cover Gasket Transfer Plate to Case Gasket Transfer Plate to Valve Body Gasket 12 Screw and Washer Assemblies

Service Manual Reference: When servicing any 1990/1991 HYDRA-MATIC 3L30 transmission, refer to the HYDRA-MATIC 3L30 (MD2) Automatic Transmission Unit Repair Section in your service manual.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.