SQUEAL OR POPPING NOISE CRANKSHAFT PULLEY AREA. Chevrolet Chevy Suburban

MODELS: 1986 C,K,G,P 10/1500 - 30/3500 EQUIPPED WITH THE 4.3L (VIN CODE N), 5.OL (VIN CODE F,H), 5.7L (VIN CODE L,M,K)

Some 1986 C,K,G,P model trucks equipped with the 4.31+ 5.01% 5.7L engines without air conditioning (A/C) may experience a belt squeal or popping noise from the crankshaft pulley area. These noises may be caused by a separation in the generator belt groove portion of the pulley.

If this condition is encountered, it can be repaired by replacing the pulley with a new design pulley. These pulleys were changed in production effective with the following VIN breakpoints.

Model Plant VIN Breakpoint ----- ----- -------------- C/K Flint - Line 1 GMC 729913 Chevrolet 426588 Line 2 GMC 528408 Chevrolet 192683 St. Louis GMC 530639 Chevrolet 119883 Janesville GMC 511469 Chevrolet 128233

G Van Lordstown GMC 518113 Chevrolet 118449 Searborough GMC 525644 Chevrolet 163060

P Detroit Assembly GMC 503976 Chassis Chevrolet 330510

PARTS INFORMATION

New Part Quantity Number Description Application Required ------ ----------- ------------ -------- 10069912 Pulley C/&I,2,3, 4.3L 1 (N) w/o A/C C / K,1,2,3, 5.0 L 1 (F,H) 5.7L (L,w w/o A/C

P2,3 5.7L (M,K) 1 w/o BM3, w/o A/C 10069913 Pulley GI,2 4.3L (N) 1 w/o A/C, V05 G3 (03-05-06) 4.3L 1 (N) w/o A/C, V05 GI,2 5.OL (F,H) I 5.7L(L) w/o A/C, V05 G3 5.7L (L,M) I w/o A/C, V05

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.