Wheel Separation Sgt. Scott Parker Highway Safety Division
Wheel Separation Overview • Statistics, 2013-2016 • Causation: o Fastener Failure o Bearing failure o other causes • Incidents • Prevention: o Driver’s pre -trip inspection o Re-Torque o Communications o Legislation
Wheel Seperation Stats, what are the numbers • For the calendar year 2016 (up to Sept 26) there were reported 56 wheel separation events. • Reported by MTO, O.P.P. and Municipal Police Services. • We know that there were more events that simply were not reported. • This numbers thus far are consistent with previous years.
Wheel Separation • Of the 56 reported events, 47 involved hub piloted wheels. What the numbers show us as • Not surprising, given that hub far as the type of wheel involved in these events piloted are the most common wheels in use. • Stud piloted wheels were involved in 8 of the reported events • Spoke wheels accounted for 1 Hub Pilot 47 event.
Wheel Separation • Based upon O.P.P. Regional Boundaries. Where the incidents are • East, NE and NW comprise occurring the majority of the Province’s 30 land mass. 25 • GTR is expected to see more 20 events due to increased volume of traffic 15 10 5 0 EAST WEST CENTRAL GTR NER NWR
Wheel Separation • 22 of the reported incidents involved wheels separating What type of vehicles are trucks. involved in these events • 19 of the events were the result of wheels separating 25 from trailers. • Power Units losing their 20 wheels while hauling a trailer 15 accounted for 11 events.. 10 5 0 Power Unit with Power unit alone trailer tow truck towed vehicle trailer
Wheel Separation What event triggered the wheel separation events • In 41 of the reported events 45 the fasteners failed resulting 40 in separation. 35 • 12 of the events resulted 30 25 from bearing failures. 20 • Events such as broken wheel 15 rims accounted for 3 of the 10 5 wheel separation events.. 0 FASTENER BEARING CRACKED RIM OTHER
Year after year Wheel Separation by Quarter comparison 2013 2014 40 40 35 35 30 30 25 25 20 20 15 15 10 5 10 0 5 1ST 2ND 3RD 4TH 0 1ST 2ND 3RD 4TH 2016 2015 25 40 35 20 30 25 15 20 Series1 15 10 10 5 5 0 1ST 2ND 3RD 4TH 0 1ST 2ND 3RD 4TH
Year after year Wheel Separation by Vehicle Type comparison 2013 2014 50 40 45 35 40 35 30 30 25 25 20 20 15 15 10 10 5 5 0 0 Power Unit Power unit trailer tow truck towed Power Unit Power unit trailer tow truck towed with trailer alone vehicle with trailer alone vehicle 2016 2015 25 50 45 20 40 35 15 30 25 10 20 15 5 10 5 0 0 Power Unit Power unit trailer tow truck towed Power Unit Power unit trailer tow truck towed with trailer alone vehicle with trailer alone vehicle
Year after year Reason for Wheel Separation comparison 2013 2014 70 80 60 50 60 40 40 30 20 20 10 0 0 FASTENER BEARING CRACKED OTHER FASTENER BEARING CRACKED OTHER RIM RIM 2016 2015 45 80 40 70 35 60 30 25 50 20 40 15 30 10 20 5 0 10 FASTENER BEARING CRACKED OTHER 0 RIM FASTENER BEARING CRACKED OTHER RIM
Year after year Geographic Regions for events comparison 2013 2014 40 45 35 40 35 30 30 25 25 20 20 15 15 10 10 5 5 0 0 EAST WEST CENTRAL GTR NER NWR EAST WEST CENTRAL GTR NER NWR 2016 2015 30 50 45 25 40 35 20 30 25 15 20 15 10 10 5 5 0 EAST WEST CENTRAL GTR NER NWR 0 EAST WEST CENTRAL GTR NER NWR
Year after year Which vehicles are losing their wheels comparison 2013 2014 50 40 45 35 40 30 35 25 30 20 25 15 20 15 10 10 5 5 0 0 Power Unit Power unit trailer tow truck towed Power Unit Power unit trailer tow truck towed vehicle with trailer alone vehicle with trailer alone 2016 2015 50 25 45 40 20 35 15 30 25 10 20 15 5 10 5 0 0 Power Unit Power unit trailer tow truck towed vehicle Power Unit Power unit trailer tow truck towed vehicle with trailer alone with trailer alone
Year after year Where are the vehicles coming from comparison 2013 2014 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 ON NB Qc PE NS MA MB Al MI ON Ab Qc PE NB BC SK Al WI 2016 2015 45 90 40 80 35 70 30 60 25 50 20 40 15 30 10 20 5 10 0 0 ON Ab Qc Oh NY TBD2 TBD3 ON Ab Qc BC Az
Wheel Separation What causes this to happen?
Wheel Separation (a) flat tire. Causation – Fastener failure (a.1) tire leaking, if leak can be felt or heard. (b) tire tread depth is less than wear limit. 11 (a) damaged tread or sidewall of tire. (c) tire is in contact with another tire or any Part 21. Tires (b) tire leaking, if leak cannot vehicle component other than mud-flap. (d) tire is marked “Not for highway use”. be heard. • In 41 of the reported events (e) tire has exposed cords in the tread or the fasteners failed resulting outer sidewall area. in separation. • Wheel fasteners are part of a (a) wheel has loose, missing or ineffective drivers daily pre-trip fastener. (a) hub oil below minimum inspection. Part 22. Wheels, Hubs and level (when fitted with sight (b) damaged, cracked or broken wheel, rim glass). Fasteners or attaching part. • Fasteners (all 8 or 10) don’t (b) leaking wheel seal. (c) evidence of imminent wheel, hub or bearing failure just fail, occurs over time. • Why is it being missed
Wheel Separation Anatomy of a fastener failure
Wheel Separation Anatomy of a fastener failure • Left side fastener failure of axle 2 • Recovered fasteners • Studs were still mounted and protruding from the brake drum
Wheel Separation Anatomy of a fastener failure • Some damage to threads on the wheel studs visible • Relative location of damage on wheel studs is consistent
Wheel Separation Anatomy of a fastener failure • In this event we recovered 7 of the 10 flange type wheel fasteners • Damage to the threads is apparent.
Wheel Separation Anatomy of a fastener failure • The 2 piece flange nuts mark the outer surface of the outer rims as the clamping force is lost. • As the wheel rotates the wheel stud holes elongate
• The movement of the rim Wheel Separation against the studs increase, further Anatomy of a fastener failure elongating the stud holes. • The stud holes in the rim become marked by the threaded surface of the studs. • Fasteners release and studs may begin to break • The outer wheel separates followed by the inner
Wheel Separation Anatomy of a fastener failure • The stud hole is from the wheel rim recovered show evidence of the flange type fastener wearing into the metal of the rim. • The evidence of elongation of the stud holes is obvious..
Wheel Separation Anatomy of a fastener failure • The evidence of abnormal contact between the stud and the rim’s stud hole is obvious.
Wheel Separation Anatomy of a fastener failure • Another example of abnormal contact between the stud and the stud hole is obvious.
Wheel Separation Anatomy of a fastener failure • Elongation of stud holes is apparent
Wheel Separation Anatomy of a fastener failure • The damage to the threads is typical of what we find when a fastener fails • The grinding away of the threads is related to the abnormal contact being made between the wheel rim stud hole and the stud due to elongation of the stud hole.
Wheel Separation Anatomy of a Bearing failure
Wheel Separation Anatomy of a Bearing failure • Generally when a bearing fails on a tandem wheel, both wheel separate as one unit. • The case study I have is on a steering axle
Wheel Separation Anatomy of a Bearing failure • The inboard bearing is still present. • From the photo the lack of lubrication is obvious. • The bearing failed, most likely due to insufficient lubrication. • Why this occurred is apparent as we look at other wheels on the truck.
Wheel Separation Anatomy of a Bearing failure • Axle two, right side. • What do you notice about the sight glass? • Proper pre-trip?.
Wheel Separation Anatomy of a Bearing failure • Axle two, right side. • What do you notice about the sight glass? • Proper pre-trip?.
Wheel Separation Anatomy of a Bearing failure • Axle four, left side. • All sight glasses were in the same condition on each wheel? • Preventable?
Wheel Separation Anatomy of a Bearing failure • Lets look at the wheel opposite to the bearing that failed, axle one, left side.
Recommend
More recommend
