D 350 Pickup L6-359 5.9L DSL (1989)
Technical Service Bulletin # 060190A
Date: 901231
M/T - Cyclic Groaning Noise at Low Rpm
SUBJECT:
Powertrain Induced Transmission Noise Below 1400 RPM - Truck Equipped With Cummins Engine And Manual Transmission
NO.:
06-01-90
REVISION A
GROUP:
CLUTCH
DATE:
Dec. 31, 1990
MODELS:
1989 - 1991
(AD) - DODGE RAM PICKUP, RAM CAB & CHASSIS (RWD, 4WD)
POWER RAM CAB & CHASSIS (4WD)
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 06-01-90, WHICH SHOULD BE REMOVED FROM YOUR FILES. ALL
REVISIONS ARE INDICATED WITH >> ARROWS <<.
SYMPTOM/CONDITION:
Some 1989 and 1991 Ram trucks equipped with the Cummins Diesel and manual transmission may exhibit a powertrain induced cyclic groaning or harsh
noise condition that appears to be transmission or driveline related. This condition, which is not damaging or durability related, is most noticeable in
fourth and fifth gears when the engine is below 1400 RPM during float, coast, or light throttle operation.
DIAGNOSIS:
Road test the vehicle a sufficient distance to ensure the transmission has reached normal operating temperature. Evaluate the vehicle for the noise
condition in each gear during float, coast, and light throttle operation. Record the vehicle speed (MPH) above which the noise condition is no longer
present for each gear. Compare your recorded MPH readings in each gear with the recommended minimum operating gear selection chart below.
If an objectionable noise condition is present at speeds above the MPH on the chart perform the following repair procedure.
If the noise condition is only present at speeds below the MPH on the chart no repair is required as it will not be effective. A road test should be
performed with the vehicle owner using the recommended gear speed chart to ensure the owner understands the noise condition is the result of operating
the engine below the recommended RPM and not a defect in the transmission/driveline system.
Repair Procedure:
>> This repair involves the removal of the transmission and replacement of the flywheel. Vehicles built before April 1990 may also require a clutch disc.
<<
1.
Disconnect the battery negative cable.
2.
Remove shift lever boot and seal.
3.
Shift the transmission into neutral.
4.
Remove the snap ring in the shift tower that retains the stub shifter and shifter seat.
5.
Remove the shifter seat and shift lever/stub shifter assembly from the shift tower.
6.
Raise vehicle.
