K 1500 Truck 4WD V8-393 6.5L DSL VIN P (1995)
Flywheel: Technical Service Bulletins
Labor - M/T Flywheel, Yoke, Rear Housing R&R Revised
File In Section: 7 - Transmission
Bulletin No.: 66-72-02B
Date: March, 1997
Subject:
Manual Transmission Rattle Noise at Idle (Install Conventional Flywheel)
Models:
1992-96 Chevrolet and GMC C/K 2-3 Models
with 6.5L Diesel Engine (VIN's F, P - RPO's L65, L49) and NV45OO 5 Speed Manual Transmissions (RPO's MW3, MT8)
This bulletin is being revised to change a labor operation number. Please discard Corporate Bulletin Number 66-72-O2A (Section 7 - Transmission).
Condition
Some owners may comment about a rattle or banging noise from the transmission while the engine is idling, the clutch engaged (clutch pedal released)
and the transmission is in neutral. This condition is more likely to occur on a vehicle that idles for prolonged periods of time. This rattle should not be
confused with normal roll-over noise (turning bearing/whirring noise) which is generated while the transmission is in neutral, clutch engaged and engine
idling.
Cause
Failure of the hysteresis damper inside the dual mass flywheel (DMF).
Correction
Install a conventional flywheel, revised clutch kit and a transmission damper. These revised parts are currently installed in 1997 model trucks.
Important:
Installation of these parts will result in some drive rattle (transmission growl) when driving at about 900 RPM or less. Normal DMF shut-down rattle
will be eliminated if the clutch is disengaged (pedal depressed), but rattle will occur if the engine is shut-off with the transmission in neutral and the
clutch engaged (foot off pedal). This rattle is from the transmission and can not be eliminated by transmission repair or replacement.
Service Procedure
Refer to the appropriate year Service Manual Section 7C for clutch replacement procedures. When installing the new flywheel, the retaining ring from
the DMF is not used.
4-Wheel Drive: The damper is installed between the transmission and the transfer case. To install the damper, the transmission rear extension housing
must be removed. Refer to the appropriate year Unit Repair Manual, Section 7B8, NV4500 Manual Transmission for details. When installing the damper
nut, apply Loctite(R) 242, P/N 12345493, to the nut threads and torque the nut to 325 lb ft (441 N.m).
2-Wheel Drive: The damper is part of the yoke assembly. Replacement of the yoke is required. To install the yoke, refer to the appropriate year Unit
Repair Manual, Section 7B8, NV4500 Manual Transmission. When installing the yoke/damper nut, use Loctite(R) 242, P/N 12345493, on the nut
threads and torque the nut to 325 lb ft (441 N.m).
Important:
Yoke/Damper not used on 15,000 lb Models
The following fastener tightening specifications should be used:
^
Rear extension-to-case bolts 40 lb ft (54 N.m)
^
Flywheel-to-crankshaft bolts 65 lb ft (90 N.m)
^
Pressure plate-to-flywheel bolts 25 lb ft (35 N.m)
Notice:
This transmission requires a special synthetic lubricant, P/N 12346190. Do NOT substitute any other lubricant as internal transmission damage may
result. Transmission capacity is 4 quarts (3.78L).
