For 1990-2009 cars

# DRIVE BELT TENSIONING NEW PROCEDURE

#### MODELS AFFECTED: 1982-1985 ELDORADOS, SEVILLES, RWD DEVILLES AND BROUGHAMS

Some cars equipped with HT4100 engines may experience noise or vibration from the engine compartment which may be due to improperly adjusted accessory drive belts. Jack screw adjusters are used for tensioning drive belts on most HT4100 engine accessories. Using an improper jack screw adjustment procedure may result in an undertensioned or overtensioned drive belt causing an improper load on both the engine crankshaft and the specific accessory bearing. Following the belt tensioning procedures listed below and in the HT4100 Engine Cooling Section of the Cadillac Service Information Manual and setting tension to the specifications listed below are required for proper belt adjustment.

#### Belt Adjustment Procedure - Revision

A revised service procedure has been developed for tensioning the AIR pump belt. It is recommended that the generator belt be loosened prior to tensioning the AIR pump belt. This procedure is used to assure proper tensioning on all sides of the AIR belt, and will be included in the next revision of the 1985 Service Information Manual.

For warranty purposes, use the following labor Operation:

J0657 .4 Hr. Drive Belt Adjust

#### Belt Tension Specifications

The following chart supersedes all previous charts, and should be used in conjunction with belt tensioning gage, J-23600 when tensioning new and used accessory drive belts.

#### NOTICE: A belt having over 500 miles of use is considered a used belt.

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.