Tires and Wheels - Steering Wheel Vibration
NUMBER:
22-04-99
GROUP:
Wheels & Tires
DATE:
Oct. 29, 1999
SUBJECT:
Steering Wheel Vibration
MODELS:
1998 - 2000 (LH) Concorde/Intrepid/LHS/300M
OVERVIEW
This bulletin involves diagnosis and corrective information for vehicles with a steering wheel vibration.
DIAGNOSIS AND CORRECTION:
Visual Inspection of the vehicle is recommended prior to the initial test drive. Raise vehicle on a suitable hoist and inspect the following items:
^ Verify correct (original equipment) wheel and tire, as well as correct wheel weights. Aluminum wheels require unique wheel weights (after market part number "LH").
^ Inspect tires and wheels for damage, mud packing and unusual wear; correct as necessary.
^ Check and adjust tire pressure to the pressure listed on the label attached to the rear face of the driver's door.
Road Test on a smooth road for at least 5 miles to warm tires (remove flat spots).
^ Lightly place hands on steering wheel at the 10:00 and 2:00 positions while slowly sweeping up and down from 55 to 70 MPH.
^ Observe steering wheel for:
Visual Nibble (oscillation: clockwise/counter clockwise, usually due to imbalance)
Visual Buzziness (high frequency, rapid vibration up/down)
^ Rule out vibrations due to powertrain or brakes by:
^ Lightly apply brakes; if vibration occurs or is enhanced, vibration is likely due to causes other than tire/wheel assemblies.
^ Shift transmission into neutral while vibration is occurring; if eliminated, vibration is likely due to causes other than tire/wheel assemblies.
^ For powertrain or brake vibrations refer to pages 5-11 and 5-16 of the 2000 Concorde/Intrepid/LHS/300M service manual (Publication No.81-270-0040). For tire and wheel assembly vibrations, continue with this procedure.
Balance equipment must be calibrated and maintained per equipment
manufacturer's specifications.
^ Balance assemblies off vehicle dynamically and statically to less than .25 ounce.
^ Rotate assembly 180 degrees on balance equipment and verify balance; variation should not be more than .0125 ounce. If variation is more than .0125 ounce, balancing equipment could be malfunctioning.
^ If difficult to balance, break down tire/wheel assembly to check for loose debris inside tire.
^ Road test vehicle for at least 5 miles. If vibration persists, continue with this procedure.
Radial Runout must be checked starting with system check, including hub, wheel, and tire.
^ Check system runout using Miller Special Tool D-128-TR or equivalent. Apply masking tape around the circumference of the tire in the location that is to be measured (Figure 1).
^ System runout can be verified by re-indexing the tire/wheel assembly on the hub. If reindexing the tire/wheel assembly corrects or reduces the system runout, check the hub runout as described on page 5-16 of the 2000 Concorde/Intrepid/LHS/300M service manual (Publication No.81-270-0040) and repair as necessary. If the system runout is still excessive continue with this procedure.
^ Check tire/wheel runout at inner and outer shoulder with assemblies off vehicle (Figure 1) Assembly runout should be less than .040" with no tread "dips" or "steps". Tread "dips" and "steps" can be identified by by spikes in the runout gauge.
^ Tread "dips"; Rapid decrease then increase in run out greater than .025" over 4" of tread circumference.
^ Tread "steps"; Rapid decrease or increase in runout greater than .025" over 4" of tread circumference.
^ If runout exceeds limits, mark original location of tire on wheel and dismount tire to verify wheel vs. tire contribution.
^ Radial runout of the wheel measured at the tire bead seat should not exceed .010" for aluminum wheels and .020" for steel wheels as described on page 22-9 of the 2000 Concorde/Intrepid/LHS/300M service manual (Publication No.81-270-0040).
^ Tire/wheel assembly runout can be improved by re-indexing the tire to the wheel 180 degrees, as described in the Tire and Wheel Match Mounting Procedure on page 22-6 of the 2000 Concorde/Intrepid/LHS/300M Service Manual (Publication No.81-270-0040).
^ Road test vehicle for at least 5 miles. If vibration persists, and all components tested are within specification, the tires may have an excessive radial force condition. Radial forces can only be checked as indicated below. If this equipment is not available consult with the tire manufacturer.
Radial Forces can be checked using the Hunter GSP 9700 Vibration Control System (balancer), if available. Use the following reference values for measuring assembly radial forces when diagnosing vibration complaints:
Total Radial Force Variation (RFV) Less Than 20 Lbs.
Radial First Harmonic (R1H) Less Than 14 Lbs.
Radial Second Harmonic (R2H) Less Than 9 Lbs.
Radial forces greater than the reference values do not automatically mean the tire is out of specification. Be sure to examine the wheel runout. Assembly RFV and R1H can often be reduced by re-indexing the tire on the wheel.
POLICY: Information Only