PREVOST X3-45 Multiplex, Maintenance Manual

Page: 712 / 1422

8
3
Dimension
checks
3-4
Open side circumference check
WARNING Wheels that have been subjected to high pressure tire and rim
separation or excessive heat damage may no longer have sufficient dimension
and contour to retain the tire bead while under pressure.
Exploding wheel/tire assembly can cause serious injury or death.
Immediately and permanently remove from service any wheel that has been
exposed to high pressure tire and rim seperation or excessive heat.
Ball tapes used for measuring wheel circumference can be purchased from the Tire and Rim Association, Inc.,
175 Montrose West Avenue, Copley, Ohio 44321. (330) 666-8121 or at www.rma.org. For instructions on
proper use of ball tape, reference the current Tire and Rim Association yearbook.
Measure the circumference of the bead seat on the open side (see illustration
to left) with a ball tape.
The circumference of the bead seat on the open side of the wheel should
be checked at each tire change. The open side is the side opposite the disc
face. In the case of center flange wide base wheels, or wheels with insets less
than 3 inches, both rim flanges should be checked. Any wheel should be
inspected prior to mounting. If the circumference of the bead seat does not
match the required dimension as indicated by the TRA certified ball tape,
immediately and permanently remove the wheel from service.
WARNING
THIS INSPECTION TECHNIQUE ONLY APPLIES TO DUAL OR DISC FACED WHEELS
Check all wheels at each tire change for proper contour of the open side of the rim. Place the long leg of a
carpenters square across the center of the disc side of the wheel. Extend the short leg across both rim flanges of the
wheel as shown above. Repeat this process at four equidistant points around the wheel.
The short leg should touch both rim flanges at each point. If a distance greater than the thickness of a credit
card (or .030 in. or .76mm feeler gauge) appears between the short leg and the rim flange, the wheel should be
removed from service and scrapped.
Best Inspection
Method
Photo to the right
shows the TRA Ball
Tape
2nd Best Inspection
Method
If a ball tape is
unavailable
Photo above shows carpenter square even on
both bead seats.
Photo above shows and undersized wheel
that you can clearly place a credit card
(approximately .030 in. or .76mm) between
the square and the wheel.
ACCEPtABLE
UNACCEPtABLE
WARNING
WARNING Wheels that have been run flat or have other physical damage may no longer
have sufficient dimension and contour to retain the tire bead while under pressure.
Rims that lack proper dimension and contour can lead to explosive separation of the tire
and rim, causing serious injury or death.
Any wheel that has been in service must be inspected prior to mounting. Follow
dimension check procedures described in this section during each wheel inspection.
If a ball tape or carpenters square is unavailable, roll the unmounted wheel, without a tire, a minimum of 10 feet
over a smooth, flat, level, clean surface such as asphalt or concrete pavement. Any deviation from rolling in a
straight line is an indication of a potential lack of proper dimension and contour. Remove the wheel from service
until it can be properly checked with a ball tape.
3rd Best Inspection
Method
Rolling wheel as
described on this
page.
IF YOU DO NOt FULLY UNDERStAND ANY OF tHESE INSPECtION MEtHODS AS DESCRIBED
IN tHIS SECtION CONtACt ALCOA At 800-242-9898 FOR CLARIFICAtION.
Dual wheel
Non-Dual wheel