Tires/Wheels - Vibration/Shimmy
No: 60/02/03/NAS
Ref:
179
*Issue: 3*
*Date: 27 February 2004*
Steering/Tire Vibration Correction
AFFECTED VEHICLE RANGE:
New Range Rover (LM)
All
Updated information shown by asterisks.
SITUATION:
VIBRATION FROM WHEELS AND TIRES
A customer may complain of steering vibration or shimmy." Sources of vibration/shimmy can be Radial Force Variation (RFV) in the wheel-tire
assemblies and also the positioning/mounting of the wheels on the vehicle.
RESOLUTION:
MATCH MOUNTING AND WHEEL/TIRE INSTALLATION PROCEDURES
In case of a customer complaint of vibration/shimmy on vehicles, follow the optimization procedures in this bulletin using a Hunter 9700/9712
balancing machine. The procedures to be followed are:
^ Tire to wheel match-mounting
The tire is positioned on the wheel so that the low point of the tire is matched to the high point of the wheel. This procedure is also referred to as
match-mounting. The Hunter 9700/9712 balancing machine performs this procedure.
^ Wheel/tire installation
The wheel/tire assembly is mounted to the vehicle's hub in a manner that allows the Radial Force high point of the assembly to be neutralized by
taking up the inherent clearance in the wheel-to-hub mating surface. The Hunter 9700/9712 balancing machine identifies the high point of the
wheel/tire assembly.
* PARTS INFORMATION *
TOOL INFORMATION:
CAUTION:
Access to a Hunter 9700/9712 wheel-balancing machine is required to perform the steps in this technical bulletin. If this tool is not available onsite,
be sure to bring the required special adapter tools to your local tire store with the Hunter 9700/9712.
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Land Rover requires that wheel/tire assemblies be mounted to the Hunter 9700/9712 using the correct centering sleeve announced in Bulletin
STEO2-13 and the 5-lug flange plate adaptor previously supplied to Retailers. (Figure 1) This mounting method provides precise balance with
the highest rate of repeatability.
*CAUTION:
Care must be taken to ensure that the balancing location cone / spindle does not contact any part of the wheel/tire assembly except the illustrated
location during the balancing procedure. If the cone contacts any other part of the wheel/tire assembly, an incorrect cone has been selected.
Mounting the Centering Sleeve properly in the wheel opening is vital to the proper location of the wheel on the balance machine. (Figure 2)*
Land Rover recommends the use of a compression tool, such as the HAW 900, to install wheel weights. This tool prevents both accidental
damage to the rim and deformation of the wheel weight clips.
REPAIR PROCEDURE
PREPARATION
NOTE:
Tires are factory "match-mounted" on the wheels by Land Rover at initial assembly. It is important to retain this mounting orientation on
vehicles where it is known that the original factory balance is still intact.
1. Refer to the Owners Handbook specification and inflate tires to proper "cold" air pressures.
NOTE:
Tire heating is REQUIRED. It is extremely vital to the match-mounting process.
2. Drive the vehicle on a 15-20 mile highway-speed road test to ensure that all flat spots are removed and to heat tires to operating temperatures.
3. Lift the vehicle off the ground immediately after the road test to minimize temporary flat spots.
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4. If tires are directional" tires, mark for installation in the same location on the vehicle after balancing. (Figure 3)
MATCH-MOUNT AND BALANCE
1. If the wheels are known to have non4actory balance or are equipped with new tires, perform the following:
^ Remove wheel assembly while tire is still warm.
^ Measure and record the Radial Force variation.
^ Perform wheel-to-tire match-mounting if balancing machine indicates necessity.
^ Record the amount of the Radial Force variation (lbs.) on the inside of tire with crayon
CAUTION:
For rim-mounted wheel weights, use only Land Rover specification two-piece clip-on wheel weights.
NOTE:
Inner edge of compression tool must be placed close to rim. Outer swivel foot of compression tool must be placed onto shoulder of tire.
^ Balance wheel on the Hunter 9700/9712, installing two-piece weights *(Figure 4)* as follows:
^ Compress the inflated tire at the bead and the shoulder with compression tool.
^ Insert the wheel weight clip between the tire bead and the road wheel. *(Figure 5)*
^ Release the compression tool.
Spread the wheel weight clip using the two-piece Haweka clip tool HAW 900/1.
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^ Slide the weight under the clip. (Figure 6)
^ Verify that the weight is fully seated.
2. If the wheels are known to have the original factory balance intact, perform the following:
^ Remove wheel while still warm.
^ Measure Radial Force variation for wheel, but do not disturb factory wheel weights.
^ Record the amount of the Radial Force variation (lbs.) on the inside of tire with crayon
3. Perform the following steps on wheel/tire assembly:
^ Mark high point spot indicated by Hunter 9700/9712 on the tire with a hash mark on the outer sidewall.
^ Mark the high spot with a permanent white paint mark on the inside sidewall to identify for future repair situations.
4. Verify correct balance for wheel/tire assembly.
5. If the balancer indicates no additional weight is necessary ("0.00g"), loosen the wing nut, gently rock the wheel on the balancer spindle
adapter and tighten wing nut.
6. Verify balance a second time.
7. If the balancer indicates "0.00g", remove the wheel from the machine.
8. If the balancer does not indicate 0.00g perform the following:
^ Add the necessary weight.
^ Verify balance and repeat as required to achiever repeatable "0.00g" readings when the wheel is removed from the balancer
9. Go to Step 1 or Step 2 and perform complete "Match-mount and Balance" steps for each wheel/tire assembly.
MOUNT TIRES TO VEHICLE
1. If vehicle is equipped with directional tires (Figure 1), mount tires in original locations.
NOTE:
On vehicles with directional tires the wheel and tire assemblies can only be optimized at their original location on the vehicle. Step 2 does
NOT apply to directional tires.
2. If vehicle does NOT have directional tires, mount tires in the following locations:
^ Lowest value of Radial Force variation on left front of vehicle
^ Second lowest value of Radial Force variation on right front of vehicle
^ Third lowest value of Radial Force variation on left rear of vehicle
^ Highest value of Radial Force variation on right rear of vehicle.
3. Tighten wheel nuts to a snug "finger tight" condition (no wobble evident between the wheel and mounting surface).
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4. Rotate each wheel so that the previously marked high point is at the bottom (6 o'clock position) and will contact the floor when the vehicle is
lowered.
5. Lower the vehicle partially to the floor so that light-to-moderate load is placed on each of the wheels.
6. Torque the lug nuts of each wheel to 140 Nm (103 lb/ft.).
7. Road test the vehicle.
