Engine - Belt Squeal/Pop Noise From Crankshaft Pulley

CHEVROLET NUMBER: 86-T-214

SECTION: 6 - Engine Diagnosis

DATE: January, 1987

SUBJECT: CRANKSHAFT PULLEY

MODELS: 1986 C, K, G, P 10/1500 - 30/3500 EQUIPPED WITH THE 4.3L (VIN CODE N), 5.0L (VIN CODE F, H) 5.7L (VIN CODE L, M, K)

Some 1986 C,K,G,P model trucks equipped with the 4.3L, 5.0L, 5.7L engines without air conditoning 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
Scarborough GMC 525644
Chevrolet 163060

P Detroit Assembly GMC 503976
Chassis Chevrolet 330510

PARTS INFORMATION

New
Part Quantity
Number Description Application Required

10069912 Pulley C/K,1,2,3, 4.3L 1
(N) w/o A/C

C/F,1,2,3, 5.0L 1
(F,H) 5.7L (L,M)
w/o A/C

P2,3 5.7L (M,K) 1
w/o BM3, w/o A/C

10069913 Pulley G1,2 4.3L (N) 1
w/o A/C, V05

G3 (03-05-06) 4.3L 1
(N) w/o A/C, V05

G1,2 5.0L (F,H) 1
5.7L (L) w/o A/C, V05

G3 5.7L (L,M) 1
w/o A/C, V05