R 1500 P/U 2WD V8-350 5.7L (1987)
Muffler: All Technical Service Bulletins
Exhaust System - Noisy/Low Hanging Muffler
GMC NUMBER:
88-T-162
GROUP:
6F - Engine Exhaust
DATE:
February, 1989
CORPORATE
NUMBER:
866602
SUBJECT:
NOISY SOUNDING OR LOW HANGING MUFFLER
MODELS:
1987-88 SUBURBAN WITH 5.7L, 7.4L ENGINE (VIN CODE K AND N)
Customer comments may be received on 1987 and 1988 KV Models built prior to VIN breakpoints (GMC-JF527803 and Chevrolet JF165082) equipped
with 5.7L or 7.4L engine, of low hanging or throaty sounding (rumbling on acceleration) mufflers. Mufflers designed for usage on TBI equipped engines
are of a high flow/low restriction design for improved engine performance and are somewhat louder than mufflers used in previous years. If either of
these conditions are experienced, they can be repaired by installing a revised muffler and tailpipe assembly.
PARTS INFORMATION
Parts
Qty.
Number
Description
Application
Req'd
15616421 Muffler
R1, 2 5.7L Federal (NA5/NA6) 1
R2 7.4L Export (NM8)
15616422 T/pipe
R1, 2 5.7L Federal (NA5/NA6) 1
R2 7.4L Export (NM8)
15616423 Muffler
R2 5.7L Calif. (NB2)
1
R2 7.4L Federal (NA5/NA6)
15616424 T/Pipe
R2 5.7L Calif. (NB2)
1
R2 7.4L Federal (NA5/NA6)
15616425 Muffler
V1, 2 5.7L Federal (NA5/NA6) 1
15616426 T/Pipe
V1, 2 5.7L Federal (NA5/NA6)
379360 Clamp
R/V 1, 2 5.7L only
1
15624612 Hanger Muffler V1, 2 only
16624613 Shield Muffler
All
1
14029140 Bracket, Shield
All
2
15549331Hanger T/Pipe
R1, 2
1
15549332Hanger T/Pipe
V1, 2
1
435611
Bolt 3/8" - 16 x 1.00" All
2
103321
Washer 3/8" Flat
All
2
9414034 Nut 3/8" - 16
All
2
180083
Bolt (T/Pipe Hgr)
R1, 2
1
5/16 x 18 x 1.5"
V1, 2
2
9439511 Washer (T/Pipe Hgr)
R1, 2
1
5/16 Lock
V1, 2
2
9439493 Nut T/Pipe Hgr)
R1, 2
6
5/16 x 18 x 14
V1, 2
9
9418918 Bolt (Conv Shld
T/Pipe Hgr)
(R Model) 5
5/16 x 18 x 1"
All
(V Model) 8
11514363 Bolt (Conv Shld)
M6 x 1 Self Tapping
All
1
456846 J-Nut (Conv Brkt)
5/16 x 18
All
2
2436162 Washer (Conv Shld)
5/16 Flat
All
2
Parts are currently available from GMSPO. When making the above changes to the exhaust system, it is necessary to replace the muffler heat shield to
maintain proper passenger compartment temperature. It is also necessary on V models to add a secondary T/Pipe hanger to maintain proper alignment.
On all models it will also be necessary to replace the tailpipe hanger.