1800-2400 RPM VIBRATION INSTALL ENGINE BRACES

1983-84 S/T TRUCK WITH 2.0L ENGINES

Some 1983-84 S/T Trucks equipped with the 2.0L engine may experience a vehicle vibration between 1800-2400 RPMs. This condition may be present on trucks equipped with either a manual transmission or an automatic transmission.

If the subject condition is encountered, the vehicle should be inspected to see if the truck is equipped with support braces as shown in the following illustrations. If the truck is not equipped with the braces, the illustrations and parts lists contain the part numbers for the braces, attaching brackets, and fasteners. Installation of these parts will eliminate the condition.

NOTICE: Manual transmissions can be identified as follows: The Borg Warner 4 & 5-speed manual transmissions have a separate clutch bell housing, where the Isuzu transmission and clutch housing is one complete casting.

NOTICE: All the fasteners used are METRIC, and U.S. STANDARD FASTENERS must not be substituted. Use only the fasteners listed. The torque for all fasteners is 40-54 N.m. (30-40 ft. lbs.).

Vehicles equipped with Borg Wamer manual transmissions (4 or 5-speed) will require the following parts (see Illustrations No. 1, 2, 4, and 5):

Quantity Item P/N -------- ---- --- 1 Engine Bracket 14055732 3 Bolts 11504596 5 10mm Lock Washers NPN 1 Nut 11505057 1 RH Engine Brace 14041520 1 LH Engine Brace 14055731 1 Bolt 14060130 2 Nut 11504039 2 Transmission Brace (RH & LH) 14068709 2 Bolt 11508897 1 Bolt 11502667 1 LockNut 11504975

NOTE: Transmission braces must be installed with slotted end toward the rear of the transmission (see Illustration No. 2). Non power steering units will require spacer, P/N 15598576, (see Illustration No. 3).

Vehicles equipped with Isuzu built manual transmissions (4-speed) will require the following parts (see Illustrations No. 1, 3, and 4):

Quantity Item P/N -------- ---- ---- 1 Engine Bracket 14055732 3 Bolts 11504596 5 10mm Lock Washers NPN 1 Nut 11505057 1 RH Engine Brace 15597402 1 LH Engine Brace 15597401 1 Bolt 14060130 2 Nut 11504039

NOTE: Non power steering units will require spacer, P/N 15598576, (see Illustration No. 3).

Vehicles equipped with automatic transmissions will require the following parts (see Illustrations No. 1 and 5):

Quantity Item P/N -------- ---- --- 1 Engine Bracket 14055732 6 Bolt 11504596 7 10mm Lock Washer NPN 1 Nut 11505057 1 RH Engine Brace 14041520 1 LH Engine Brace 14055731

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.