Steering - Front End Shimmy On Rough Roads
NUMBER: 22-005-06GROUP: Tire & Wheels
DATE: October 07, 2006
SUBJECT:
Front End Shimmy On 4x4 Vehicles When Traveling Over Rough Surfaces In The Road
OVERVIEW:
This bulletin involves verifying the condition of the vehicle front suspension and steering components, and adjusting the front tire pressure.
MODELS:
2003 - 2007 (DR/DH/D1/DC) Ram Truck (2500/3500)
NOTE:
This bulletin applies to four wheel drive (4x4) 2500 and 3500 model vehicles.
SYMPTOM/CONDITION:
The customer may experience a self sustaining vibration (shimmy) felt in the front end of the vehicle after striking a bump or pothole.
DIAGNOSIS:
If the customer experiences the above condition perform the Repair Procedure.
PARTS REQUIRED:
SPECIAL TOOLS/EQUIPMENT REQUIRED:
REPAIR PROCEDURE:
1. Raise the vehicle on an alignment rack (drive-on lift).
2. Verify the road tires are correctly sized and the tire tread is not excessively worn. Replace any worn tire before proceeding. Any new or old replacement tire should be equal to the original tires that came with the vehicle when it was new. Tire wear is not covered by the vehicle warranty.
3. Set the tire pressure for the FRONT TIRES to the following specification, regardless of the load being carried by the vehicle.
4. Set the tire pressure for the REAR TIRES as recommended for the vehicle configuration and load that is being carried at the time.
5. Verify that the steering damper is operating correctly.
a. Unbolt the end of the damper at the axle end.
b. Cycle the damper rod by hand.
c. There should be resistance to motion in both directions of the damper rod.
d. Replace the damper if no resistance is present.
6. Verify both outer tie rod ends dust covers are not worn.
a. Attempt to rotate the dust cover by hand.
b. If the dust cover on an outer tie rod end can be rotated, or is free and loose, then replace the tie rod (regardless of joint wear).
7. Inspect each outer tie rod end for internal wear.
a. Maximum allowed wear (joint travel) for a tie rod end is 1.15 mm (0.045 in.).
b. Install a dial indicator to the tie rod end (in-line with the vertical stud of the tie rod end).
c. With a pry bar placed between the steering linkage and the axle tube, pry upwards while measuring the amount of joint travel (wear).
d. Measure the amount of wear in the other outer tie rod end joint.
e. If wear (joint travel) in either outer tie rod end is greater than 1.15 mm (0.045 in.), then replace the worn tie rod end.
8. Verify the torque on each outer tie rod end stud nut. The nut should be tightened to 122 Nm (90 ft. lbs.).
9. Make sure any worn outer tie rod ends have been replaced before proceeding further.
10. Verify all other steering linkage connections are tightened to their torque specifications.
11. Grease both outer tie rod ends (even if the outer tie rod is new). Apply sufficient grease to each tie rod end until grease is seen purging from the joint at the dust seal.
12. Align the vehicle front end. Adjust to specifications.
13. Road test the vehicle and verify the shimmy condition has been corrected.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
FAILURE CODE:
Disclaimer:
This bulletin is supplied as technical information only and is not an authorization for repair.