SHIFT LEVER RATTLE/BUZZ NOISE IN 3RD. OR 4TH. GEARS ISUZU

MODELS AFFECTED: 1985-87 SKYLARKS WITH MANUAL TRANSAXLE 1985-89 SKYHAWKS WITH MANUAL TRANSAXLE

This bulletin supersedes Buick Service Bulletin 86-7-4A. Bulletin 86-7-4A should be discarded.

Engine VIN "O" pertains to 1.8L; engine VIN "U" pertains to 2.5L; and the other VIN numbers pertain to 2.0L engines.

Some 1985-89 Skyhawk and Skylarks equipped with Isuzu 5-Speed manual transaxles may exhibit a rattle or buzzing type noise through the shifter handle while driving in 3rd or 4th gears. This noise condition is normally caused by a runout condition between the 3-4 synchronizer and the 3rd or 4th input gears.

This condition has been corrected during the 1989 model year. Therefore any 1989 vehicle equipped with an Isuzu unit built on or after a transmission serial number IX17JOl (October 17, 1988) should not have this condition. The serial number is printed on the transmission bar code label, which is located on the clutch housing. The serial number should be read as follows:

Positions l.........Corp. Name (i.e. I = Isuzu) 2.........Month of build 1-9, X, Y, or Z (i.e. 2 = Feb., 7 = July, X = Oct., Z = Dec.) 3,4.......Day of month built 1-31 (i. e. 17 = 17th day of the month) 5.........Year of build (i.e. J-Z = 1988, A-I = 1989) 6, 7......Not needed to determine build date.

Example: Unit I13OB35 = built on Jan. 30, 1989.

To repair this condition install a new 3rd/4th synchronizer assembly, 3rd/4th fork assembly, and a 3rd or 4th input gear. Refer to the following chart when ordering parts from GMSPO.

ENGINE MODEL PART DESCRIPTION BODY VIN YEAR NUMBER ----------- ---- --- ---- ------ Fork - 3rd/4th All All All 94464752

Synchronizer As All All All 94249573 - 3rd/4th

3rd Input Gear J 1 88-89 94149668 J P,1 85-87 94139574

J K,O 85-89 94149668 N U 85-89 94149668

4th Input Gear J 1 88-89 94139575 J P,1 85-87 94139576 J K,O 85-89 94139575 N U 85-89 94139575

Parts are currently available from GMSPO.

Use applicable Labor Operation Number and Time.

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.