Measuring Stud Circle
and Hub Center Runout
Theory and Information
Setup Procedure
Measurements
Specifications
Diagnostics
Theory and Information
Check the stud circle runout and the hub center
runout whenever the off-vehicle radial
and on-vehicle radial
runout are significantly different.
NOTICE: Most original
equipment wheels are centered on the hub/axle by the center hub of the
axle/hub and NOT the stud circle. Some aftermarket wheels may be
stud circle centered and more sensitive to stud circle runout problems.
Setup
Procedure
- Remove the tire and wheel assembly.
- Remove the brake rotor or drum.
- As shown below, position the dial
indicator to contact the wheel-mounting studs as close to the flange as
possible.
- Turn the hub to
register the high spot of the stud.
- Zero the dial indicator.
Measurements
Stud Circle
Runout Check
- Turn the hub to measure the next stud.
- Turn the hub to
register the high spot of the stud.
- Record the dial indicator reading.
- Compare the high spot reading of this stud with zero in the
dial indicator.
- Repeat this process for all of the studs.
- Compare the lowest reading to the highest reading, this is
the stud circle runout.
-
Compare the amount of runout to the specifications listed
below.
Specifications
Maximum Stud circle runout is typically
0.010 inch (0.254mm)
Diagnostics
- If the runout is out of specifications, replace the axle shaft or hub and
bearing assembly that you are measuring. Re-measure the stud circle
runout to ensure the new component is within specifications.
- If the runout is within specifications, perform the hub
center runout test shown below.
- Road test the vehicle. If the vibration concern has
been corrected, return the vehicle to the customer.
Hub Center Runout
Setup
Procedure
-
As shown below, position the dial
indicator on the machined surface of the hub, axle flange, or rotor, outside
the wheel studs as shown below.
-
Rotate the hub
to find the low spot.
-
Set the dial indicator
to zero at the low spot.
Measurements
Hub Center Runout Check
-
Rotate the hub
again to check the total amount of runout.
-
Compare the amount of runout to the specifications listed
below.
Specifications
Maximum hub center runout is typically
0.000 inch (0.000mm)
Diagnostics
- If the runout is out of specifications, replace the axle shaft or hub and
bearing assembly that you are measuring. Re-measure the hub center
runout to ensure the new component is within specifications.
- If the runout is within specifications, road test the vehicle. If
the vibration concern has been corrected, return the vehicle to the customer.
- If the vehicle still exhibits a first
order tire speed related vibration
on the road test, click here
to learn about tire sidewall problems.
This page was last modified
Thursday, March 05, 2009 09:02:05 PM
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