DodgeRam.info > TSB's > 1985-1993 Ram > 06-01-90A

TSB 06-01-90 Revision A

Powertrain Induced Transmission Noise Below 1400 RPM

Visit Geno's Garage for Truck accessories.

Date: Dec. 31, 1990

Models: 1989 - 1991 (AD) - DODGE RAM PICKUP, RAM CAB & CHASSIS (RWD, 4WD)
                                                 POWER RAM CAB & CHASSIS (4WD)

Symptom/Condition:

Some 1989 and 1991 Rain 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.

GEAR	AXLE RATIO
	3.54 Axle Minimum Speed	4.10 Axle Minimum Speed
First	5 MPH	4 MPH
Second	10 MPH	9 MPH
Third	20 MPH	17 MPH
Fourth	30 MPH	26 MPH
Fifth	45 MPH	40 MPH

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 he 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.  

Parts Required:

1 - Disc, Clutch    PN 53009812
4 - Bolts (if required)   PN 6024473 lose
1 - Flywheel Assembly    PN 53020120  

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.

7.    Mark the propeller shaft(s) universal joint and transmission and axle yoke for alignment reference at installation.

8.    Remove the propeller shaft(s).

9.    Disconnect the speedometer cable, back-up light wiring, and transfer case linkage if equipped.

2WD TRANSMISSION:

10A.   Support the transmission with a suitable jack.

11A.   Remove the crossmember.

4WD TRANSMISSION:

10B.   Support the crossmember and transmission/transfer case assembly with a suitable jack. Using "C" clamps and safety chain secure the assembly to the jack.

11E.   Remove the crossmember to frame bolts.

12. Remove the four transmission to clutch housing bolts.

NOTE: MEASURE THE BOLTS. IF THEY ARE 7/16-14 X 1 1/2 INCHES THEY MUST BE REPLACED WITH PN 6024473 (7/16-14 X 2 INCHES)

13.   Lower the transmission slightly, move the assembly rearward until the input shaft clears the clutch housing and remove the transmission from under the vehicle.

14.   Remove the exhaust support bracket located on the right side of the clutch housing.

15.   Remove the clutch release cylinder and cover.

16.   Remove the clutch housing.

17.   Loosen the clutch cover bolts evenly a few threads at a time to avoid warping the cover.

18.   Remove clutch cover and disc. Double-Check the clutch disc part number, (the PN is located on the flywheel side of the disc). If the disc PN is 4429151 the disc must be replaced. If the PN is 53009812 the disc should be reinstalled unless it is worn or damaged.

19.   Remove the flywheel.

20.   Clean the friction face of the clutch cover with a suitable solvent such as Mopar Brake and Carburetor Parts Cleaner PN 4318037. The friction face must be free of dirt and oil. Do not clean the release bearing with any solvent.

21.   Inspect the pilot bushing in the old flywheel, it should be smooth and show no excessive wear.

NOTE:    IF THE PILOT BUSHING IS EXCESSIVELY WORN, THE CLUTCH HOUSING BORE AND FACE RUNOUT SHOULD BE CHECKED AS OUTLINED IN THE 1990 REAR WHEEL DRIVE TRUCK SERVICE MANUAL, PUBLICATION NO. 81-370-0108, PAGE 6-3.

ALIGNMENT SPECIFICATION:

CLUTCH HOUSING BORE RUNOUT .015" TIR MAXIMUM
CLUTCH HOUSING FACE RUNOUT .010" TIR MAXIMUM

OFFSET DOWELS ARE NOT AVAILABLE FOR DIESEL ENGINE APPLICATION, IF CLUTCH HOUSING BORE EXCEEDS .015" TIR, REPLACE THE CLUTCH HOUSING, AND REMEASURE THE RUNOUT. IF THE RUNOUT EXCEEDS .015" TIR WITH THE NEW CLUTCH HOUSING, REPLACE THE TRANSMISSION ADAPTER PLATE ON THE REAR FACE OF THE ENGINE.

22.   Install flywheel PN 53020120. Tighten the flywheel bolts to 101 ft.lbs. (137 N.m) torque.

23.   Lubricate the pilot bushing with Mopar Multipurpose Grease PN 4318063.

24.   Install the clutch disc and clutch cover using a universal clutch alignment tool.

25.   Tighten the clutch cover bolts a few turns at a time to avoid warping the cover. Torque the cover bolts to 17 ft-lbs (23 N.m).

26.   Clean the clutch housing and transmission adapter faces, they must be free of dirt and oil.

27.   Lubricate the clutch release lever ball pivot with Mopar Multipurpose Grease PN 4318063.

28.   Install the clutch housing, torque the mounting bolt to 35 ft-lbs (41 N.m).

29.   Install the clutch release cylinder and cover and exhaust support bracket.

30.   Install the transmission.

NOTE:    MEASURE THE BOLTS. IF THEY ARE 7/16-14 x 1 1/2 INCHES, THEY MUST BE REPLACED WITH P/N 6024473 (7/16-14 x 2 INCHES).

31.   Apply Mopar Stud N' Bearing Mount PN 4318032 to the transmission bolt threads.

32.   Install the transmission bolts and torque to:
             7/16 in. bolt 65 ft-lbs (88 N.m).
             1/2 in. bolt 90 ft-lbs (122 N.m).

33.   Install the crossmember.

34.   Install the propeller shaft(s), be sure to align the universal joint(s) with the yoke marks made during disassembly.

35.   Install the speedometer cable and back-up light wiring.

36.   Lower vehicle.

37.   Install the stub shifter/shift lever assembly, shifter seat and snap ring.

38.   Install the shift lever seal and boot.

39.   Connect the battery negative cable.

40.   Start engine and check clutch operation.

Notes:

POLICY: Reimbursable within the provisions of the warranty.

TIME ALLOWANCE:
Labor Operation No. 06-20-01-94 . . . . . . . . . . . 2WD 2.8 Hrs.
                                                                             4WD 4.7 Hrs.
Related Operations 06-20-01-95 . . . . . . . . . . . . . 0.6 Hrs.
                              Check clutch housing bore and face runout.
                              06-25-45-90 . . . . . . . . . . . . . 0.2 Hrs.
                              Flywheel Assembly Replace.

FAILURE CODE: 68 - Noisy