00-03-10-006M

File in Section:
Bulletin No.:
Service Bulletin
Date:
03 - Suspension
00-03-10-006M
July, 2016
INFORMATION
Subject:
Information on Tire Radial Force Variation (RFV)
Models:
2017 and Prior GM Passenger Cars and Light Duty Trucks
Attention:
This Bulletin also applies to any of the above models that may be Export from North
America vehicles.
This Bulletin has been revised to add the 2017 Model Year and add a procedure for 180
matching flangeless rims. Please discard Corporate Bulletin Number 00-03-10-006L.
Important:
Before measuring tires on GM approved tire force
variation measurement equipment, the vehicle
MUST be driven a minimum of 24 km (15 mi) to
ensure removal of any flat-spotting. Refer to the
latest version of Corporate Bulletin
Number 03-03-10-007: Tire/Wheel Characteristics
of GM Original Equipment Tires.
• GM approved tire force variation measurement
equipment MUST be calibrated prior to measuring
tire/wheel assemblies for each vehicle.
Note: If the equipment being used is capable of
performing a centering check, the centering check must
be completed before taking measurements of balance
or RFV.
The purpose of this bulletin is to provide guidance to
GM dealers when using GM approved tire force
variation measurement equipment. This type of
equipment can be a valuable tool in diagnosing vehicle
ride concerns. The most common ride concern
involving tire radial force variation is highway speed
(105-115 km/h (65-70 mph) shake on smooth roads.
Tire related smooth road highway speed shake can be
caused by three conditions: imbalance, out of round
and tire force variation. These three conditions are not
necessarily related. All three conditions must be
addressed.
Imbalance is normally addressed first, because it is the
simplest of the three to correct. Off-vehicle, two plane
dynamic wheel balancers are readily available and can
accurately correct imbalance. Balancer calibration and
maintenance, proper attachment of the wheel to the
balancer, and proper balance weights, are all factors
required for a quality balance. However, a perfectly
balanced tire/wheel assembly can still be "oval shaped"
and cause a vibration.
Before balancing, perform the following procedures.
Copyright 2016 General Motors LLC. All Rights Reserved.
Tire and Wheel Diagnosis
1. Set the tire pressure to the placard values.
2. With the vehicle raised, ensure the wheels are
centered on the hub by loosening all wheel nuts
and hand-tightening all nuts first by hand while
shaking the wheel, then torque to specifications
using a torque wrench, NOT a torque stick.
3. Visually inspect the tires and the wheels. Inspect
for evidence of the following conditions and correct
as necessary:
• Missing balance weights
• Bent rim flange
• Irregular tire wear
• Incomplete bead seating
• Tire irregularities (including pressure settings)
• Mud/ice build-up in wheel
• Stones in the tire tread
• Remove any aftermarket wheels and/or tires
and restore vehicle to original condition prior to
diagnosing a smooth road shake condition.
4. Road test the vehicle using the PicoScope
(CH-51450) essential tool. Drive within posted
speed limits at 105-115 km/h (65-70 mph) for a
sufficient distance on a known, smooth road
surface to duplicate the condition. Determine if the
vehicle is sensitive to brake apply. If the brakes are
applied lightly and the pulsation felt in the steering
wheel increases, refer to the Brakes section of the
service manual that deals with brake-induced
pulsation. If you can start to hear the vibration as a
low boom noise (in addition to feeling it), but
cannot see it, the vehicle likely has a first order
(one pulse per propshaft revolution) driveline
vibration. Driveline first order vibrations are high
enough in frequency that most humans can start to
hear them at highway speeds, but are too high to
be able to be easily seen. These issues can be
Page 2
July, 2016
caused by driveline imbalance or misalignment. If
the vehicle exhibits this low boom and the booming
pulses in-and-out on a regular basis (like a
throbbing), chances are good that the vehicle
could have driveline vibration. This type of
vibration is normally felt more in the "seat of the
pants" than the steering wheel.
5. Next, record the Hertz (Hz) reading as displayed
by the PicoScope onto the tire data worksheet
found at the end of this bulletin. This should be
done after a tire break-in period of at least 24 km
(15 mi) at 72 km/h (45 mph) or greater, in order to
eliminate any possible tire flat-spotting. This
reading confirms what the vehicle vibration
frequency is prior to vehicle service and
documents the amount of improvement occurring
as the result of the various steps taken to repair.
Completing the Steering Wheel Shake Worksheet
below is required. A copy of the completed
worksheet must be saved with the R.O. and a copy
included with any parts returned to the Warranty
Parts Center for analysis. A reading of 35 to 50 Hz
typically indicates a first order propshaft vibration.
Generally, a reading between 10 and 20 Hz
indicates a tire/wheel vibration and if this is the
reading obtained, continue using this bulletin.
If the tire 1st order vibration goes away and stays
away during this evaluation, the cause is likely
temporary tire flat-spotting. Tire flat-spotting
vibration may come and go at any speed over
72 km/h (45 mph) during the first 10 minutes of
operation, if vibration continues after 10 minutes of
driving at speeds greater than 72 km/h (45 mph),
temporary tire flat-spotting can be ruled out as the
cause for vibration.
6. If permanent flat-spotting is the cause, provide the
explanation that this is the nature of the tire if the
vehicle is parked for long periods of time. Refer to
the latest version of Corporate Bulletin Number
03-03-10-007: Information on Tire/Wheel
Characteristics (Vibration, Balance, Shake, Flat
Spotting) of GM Original Equipment Tires.
7. If the road test indicates a shake/vibration exists,
check the imbalance of each tire/wheel assembly
on a known, calibrated, off-car dynamic balancer.
Make sure the mounting surface of the wheel
and the surface of the balancer are absolutely
clean and free of debris. Be sure to choose the
proper cone/collet for the wheel, and always
use the pilot bore for centering. Never center
the wheel using the hub-cap bore since it is not
a precision machined surface. Perform the
centering check if the equipment is capable of a
centering check. If any assembly calls for more
than ¼ ounce on either rim flange, remove all
balance weights and rebalance to as close to zero
as possible. If you can see the vibration (along with
feeling it) in the steering wheel (driving straight
without your hands on the wheel), it is very likely to
be a tire/wheel first order (one pulse per revolution)
disturbance. First order disturbances can be
caused by imbalance as well as non-uniformities in
tires, wheels or hubs. This first order frequency is
too low for a human to hear, but if the amplitude is
high enough, it can be seen.
Bulletin No.: 00-03-10-00SM
If a vibration or shake still exists after balancing, any
out of round conditions, of the wheel, and force
variation conditions of the tire, must be addressed. GM
approved tire force variation measurement equipment
can address both (it is also a wheel balancer).
Tire radial force vibration (RFV) can be defined as the
amount of stiffness variation the tire will produce in one
revolution under a constant load. Radial force variation
is what the vehicle feels because the load (weight) of
the vehicle is always on the tires. Although free runout
of tires (not under load) is not always a good indicator
of a smooth ride, it is critical that total tire/wheel
assembly runout be within specification.
Tire force variation measurement equipment loads the
tire, similar to on the vehicle, and measures radial force
variation of the tire/wheel assembly. Note that the
wheel is affecting the tire's RFV measurement at this
point. To isolate the wheel, its runout must be
measured. This can be easily done on GM approved
tire force variation measurement equipment, without
the need to set up dial indicators. If the wheel meets the
runout specification, the tire's RFV can then be
addressed.
After measuring the tire/wheel assembly under load,
and the wheel alone, the machine then calculates
(predicts) the radial force variation of the tire. However,
because this is a prediction that can include mounting
inaccuracies, and the load wheel is much smaller in
diameter than used in tire production, this type of
service equipment should NOT be used to audit new
tires. Rather, it should be used as a service diagnostic
tool to minimize radial force variation of the tire/wheel
assembly.
GM approved tire force variation measurement
equipment does an excellent job of measuring wheel
runout, and of finding the low point of the wheel (for
runout) and the high point of the tire (for radial force
variation). This allows the tire to be matched mounted
to the wheel for lowest tire/wheel assembly force
variation.
The machine will simplify this process into easy steps.
The following assembly radial force variation numbers
should be used as a guide:
P-Metric tires of
passenger cars
18 lbs (8 kg) or less
P-Metric tires on
light trucks
24 lbs (11 kg) or less
LT-tires on light
trucks
35 lbs (16 kg) or less
When measuring RFV and match mounting tires
perform the following steps.
Measuring Wheel Runout and Assembly Radial
Force Variation/180 Matching Procedure (Hunter)
Important: The completed worksheet at the end of this
bulletin must be attached to the hard copy of the repair
order.
Bulletin No.: 00-03-10-006M
July, 2016
If a runout/balancing machine is used record the
radial runout of the tire/wheel assemb,lies on the
worksheet at the end of this bulletin. If one or more
of the tire/wheel assemblies are more than
0.040 in (1.02 mm), match mount the tire to the
whe~l_to get below 0.040 in (1.02 mm). For
sensItIve customers, readings of 0.030 inch
(0.76 mm) or less are preferable, it may also be of
benefit to have the lowest runout assembly to the
front left corner. If the machine is not available and
the PicoScope data suggests there is an issue
swap the tire and wheel assemblies from the fr~nt
to the back. Re-check on the PicoScope and if the
problem still exists, test another vehicle to find
tires that do ~ot exhibit the same frequency and
swap those tires onto the subject vehicle.
• After match mounting, the tire/wheel assembly
must be rebalanced.
Note: Flange less wheels are commonly used today
~nd the runout cannot be measured accurately with the
tire on the wheel. There is no machined surface on the
outside of the wheel like on the flanged wheel so for an
a~curate runout measurement, the wheel should be
dismounted and a reading should be taken on the inner
bead seat area of the wheel or the (Hunter) 180
Matching procedure can be used (see below). The
runout spec is the same as a flanged wheel.
•
•
Measure radial force variation and radial runout.
If a road force/balancing machine is used, record
the radial force variation (RFV) on the worksheet
at the end of this bulletin. It may be of benefit to
have the lowest RFV assembly to the front left
corner. If the machine is not available and the
Pico~cope data suggests there is an issue, swap
the tire and wheel assemblies from the front to the
back. Re-check on the PicoScope and if the
problem still exists, test another vehicle to find
assemblies that do not exhibit the same
frequency. If the subject vehicle exhibits vibration
in the seat, then swap only the rear assemblies
and see if the problem continues. If the subject
vehicle exhibits vibration in the steering wheel,
swap only the front assemblies and see if the
problem continues. If the subject vehicle
continues to vibrate after swapping two
assemblies then swap all four. If the vibration still
exists, continue below.
Page 3
Page 4
July, 2016
Bulletin No.: 00-03-10-00SM
4540628
Legend
(1)
Flangeless Rim
180 Matching with Flangeless Wheels (Hunter
machine)
On flangeless wheels, the 180 Matching procedure can
be used when using a Hunter 3rd, 4th or 5th generation
machine. This can be used with the tire still on the
wheel.
(2)
Flanged Rim
Hunter 180 Matching Procedure (this information can
also be found in the Hunter manual for your machine):
Bulletin No.: 00-03-10-006M
July, 2016
Page 5
4540494
180 Matching will minimize Road Force® in the
tire and wheel assembly. It requires a tire changer,
as the tire will be repositioned about the wheel
during the procedure. The 180 Matching
procedure can be launched by touching the
Road Force® button, then Procedure and then 180
Matching buttons.
4540495
There is a progress bar at the top of the screen to show
how far along the procedure has progressed.
1. Mount the assembly on the balancer.
Page 6
July, 2016
2. Set the tire pressure to the vehicle manufacturer's
specification.
3. Lower the hood to start the Road Force®
measurement.
4. Position the valve stem at 12:00 and touch "Enter
Valve Stem."
5. Mark the tire with a piece of chalk or a marker with
a "V" opposite the valve stem as indicated. Touch
"OK" or tap the foot pedal when completed.
6. Use a tire changer and rotate the rim 180 degrees
relative to the tire, aligning the "V" mark with the
valve stem. Mount the assembly on the balancer.
Position valve stem at 12:00 and press "Enter
Valve Stem."
7. Lower the hood to start the Road Force®
measurement.
8. After the final spin is completed, make marks on
the tire and rim as shown on screen and
ForceMatch® the assembly.
If match mounting tires to in-spec wheels produces
assembly values higher than these, tire replacement
may be necessary. Replacing tires at lower values will
probably mean good tires are being condemned.
Because tires can sometimes become temporarily
flat-spotted, which will affect force variation, it is
important that the vehicle be driven at least 24 km
(15 mi) at 89 km (55 mph) or more prior to measuring.
Tire pressure must also be adjusted to the usage
pressure on the vehicle's tire placard prior to
measuring.
Most GM vehicles will tolerate radial force variation up
to these levels. However, some vehicles are more
sensitive, and may require lower levels. Also, there are
other tire parameters that GM approved tire force
variation measurement equipment cannot measure that
may be a factor. In such cases, TAC should be
contacted for further instructions.
Important:
• When mounting a GM wheel to a wheel balancer/
force variation machine, always use the wheel's
center pilot hole. This is the primary centering
mechanism on all GM wheels; the bolt holes are
secondary. Usually a back cone method to the
machine should be used. For added accuracy and
repeatability, a flange plate should be used to
clamp the wheel onto the cone and machine. This
system is offered by all balancer manufacturers in
GM's dealer program.
• Any type of service equipment that removes tread
rubber by grinding, buffing or truing is NOT
recommended, and may void the tire warranty.
However, tires may have been ground by the tire
company as part of their tire manufacturing
process. This is a legitimate procedure.
If the equipment being used is capable of
performing a centering check, the centering check
must be completed before taking measurements
of balance or RFV.
Steering Wheel Shake Worksheet
When diagnosing vibration concerns, use the following
worksheet in conjunction with the appropriate Vibration
Analysis-Road testing procedure in the Vibration
Correction sub-section in SI.
Refer to the appropriate section of SI for specifications
and repair procedures that are related to the vibration
concern.
Steering Wheel Shake Worksheet
To:
Dealer:
Fax Number:
VIN
Procedure Performed By:
Date:
Model:
Year:
Odometer:
VIN
TAC Case#, if applicable:
Conditions During Road Test Procedures
As condition occurs: Engine RPM _ __
Vehicle Speed_ _ __
Vibration/Noise detected during the following road test procedures:
Engine RPM _ _ _Vehicle Speed _ _ __
SIAcceleration Test: Yes _ _ _ No
Neutral Coast-Down Test: Yes _ _ _ _ No_ __
Downshift Test: Yes _ _ _ _ No_ __
Neutral Run-Up Test: Yes _ _ _ No
Steering Input Test: Yes
No
Bulletin No.: 00-03-10-00SM
Bulletin No.: 00-03-10-006M
July, 2016
Page 7
Steering Wheel Shake Worksheet
When using the PicoScope, always take a snapshot. This will help determine which vibration shows up the most.
Important: Vibrate software can also be used to assist in vibration diagnosis. Refer to Vibrate Software Description and
Operation in SI.
Vibration Analyzer Readings
Refer to Electronic Vibration Analyzer (EVA) Description and Operation in SI for more detailed information.
Important: As a reminder, place the PicoScope sensor where the vibration is mostly felt. Ensure the word "UP" on the sensor is
physically facing up. The typical areas are the seat track, the steering column or the instrument panel. Locating the PicoScope
sensor on additional area (i.e. the right fender, left fender, right quarter panel, left quarter panel, rear seat track, etc.) may also
assist in determining the component causing the vibration/noise. The key is to look for the same Hz reading with the greatest
amplitude G readings.
FILL OUT ONLY THE APPLICABLE PORTION OF THE WORKSHEET THAT APPLIES TO THE VIBRATION/NOISE:
Sensor at Steering Column:
1st Line MPH/KPH: ____ HZ: _ _ _ Gs: _ _ _ __
2nd Line MPH/KPH:
HZ:
Gs:
Sensor at Roof:
1st Line MPH/KPH: _ _ _ HZ: _ _ _ Gs:
2nd Line MPH/KPH: _ _ _ HZ:
Gs:
Sensor at Passenger Seat Rail:
1st Line MPH/KPH: _ _ _ HZ: ____Gs: _ _ __
2nd Line MPH/KPH:- - - - HZ:- - - - Gs:- - - - Tire Size and Brand:- - - - - - - Wheel/Tire Runouts on vehicle (max. 0.050 in (1.27 mm))
Refer to the latest version of Corporate Bulletin Number 00-03-10-006 for tire radial force variation.
Right rear: Inner lateral: _____ Center radial: _ _ _ __
Left rear: Inner lateral:
Center radial:- - - - Right front: Inner lateral: ____Center radial:
Left front: Inner lateral: _ _ _ Center radial:
Mounting surface runouts (max. 0.005 in (0.127 mm))
Flange, right rear: _ _ _ Hub, right front: _ _ __
Flange, left rear: ___ Hub, left front: _ _ __
Wheel stud runouts (max. 0.008 in (0.203 mm))
Flange, right rear: _____ Hub, right front: _ __
Flange, left rear: ___ Hub, left front: _ __
List Additional Repairs, If Applicable
GM bulletins are intended for use by professional technicians, NOT a "do-it-xourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide mformat1on that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.
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