NHTSA Office of Defects Investigation
Preliminary Evaluation PE23-004: Blue Bird Draglink Failures
- Closed
NHTSA's Office of Defects Investigation opened Preliminary Evaluation PE23-004 on March 17, 2023 and closed it on February 28, 2024. NHTSA's investigations file lists the Blue Bird Vision and Vision School Bus for it.
Updated daily from NHTSA's investigations file
Key facts
- NHTSA number
- PE23-004 (also written PE23004)
- Investigation type
- Preliminary Evaluation The first stage of most defect investigations: NHTSA's Office of Defects Investigation gathers basic information about a possible safety defect, including from the manufacturer.
- Status
- Closed February 28, 2024
- Opened
- Closed
- Vehicle or equipment manufacturer
- Blue Bird Body Company
- Component
- Steering — Linkages — Drag — Link — Connection
- Vehicles and equipment
- Blue Bird Vision and Vision School Bus
A recall appears here only when NHTSA's investigations file links one to the investigation; NHTSA's summary or record can name others.
NHTSA's summary
As NHTSA's Office of Defects Investigation wrote it for Preliminary Evaluation PE23-004.
On March 17, 2023, the Office of Defects Investigation (ODI) opened PE23-004 to investigate instances of drag link separation in model year (MY) 2016-2020 Vision school buses manufactured by Blue Bird Body Company (Blue Bird). Since drag links are serviceable items that can wear out, ODI opened this investigation to understand why two drag links separated at the steering arm end shortly after having passed a routine inspection by multiple qualified entities.
Two buses used in the same rural school district, owned and maintained by different bus contractors, had both undergone similar annual and semi-annual inspections prior to the start of the school year.
Both failed within a week of each other, approximately a month into the school year. ODI interviewed the bus contractors and surveyed the industry to learn what inspection methods were being used and which ones were best at detecting wear in the components.
ODI learned that the failed buses had not been inspected using the most thorough methods. ODI collected the drag links from each of the failed buses. Assisted by the Pennsylvania State Police Motor Carrier Enforcement Division and using best practice inspection methods, ODI identified and collected a pre-separation drag link from a neighboring school district. The drag links underwent a teardown inspection at the Vehicle Research and Test Center (VRTC) jointly with Blue Bird and THK-Rhythm Automotive, the drag link manufacturer.
In all cases, the visual analysis of each drag link end revealed that the grease at the steering arm end was dirty, discolored, and dry in texture, while the pitman arm end was still clean looking and fluid. ODI reviewed the information request data submitted by Blue Bird.
No other separations had been reported.
ODI contacted additional fleets to determine whether any other separations had occurred that had not been included in the submitted warranty and claim data.
None were found. The grease fitting on the steering arm end is obscured by the steering arm itself.
Therefore it is believed that inadequate maintenance resulted in the failures that had not been detected during the less-thorough prior inspections.
Blue Bird has agreed to issue a notification to all owners to clearly identify all lubrication points and ensure all owners understand the proper lubrication and inspection methods.
Blue Bird will also update their service manuals to convey the industry best practices of having someone turn the steering wheel while someone else inspects the drag links while the wheels are on the ground. Since the drag link failures appear to be caused by maintenance and inspection deficiencies and not due to a design, material or manufacturing issue, this investigation is closed.
The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The Agency reserves the right to take additional action if warranted by future circumstances.
Vehicles and equipment listed for this investigation
NHTSA's investigations file lists these vehicles and equipment for Preliminary Evaluation PE23-004. A listed model year means only that an investigation names it; it says nothing about any particular vehicle. Model years with a try.vin recall page link to that page's NHTSA investigations section.
What an NHTSA investigation is
NHTSA's Office of Defects Investigation (ODI) looks into possible safety defects in vehicles and equipment, often after owner complaints. An investigation usually starts as a Preliminary Evaluation, or as a Recall Query when it concerns whether an existing recall covers the right vehicles or fixes the problem, and ODI can upgrade it to a more detailed Engineering Analysis. A Defect Petition asks NHTSA to open an investigation, and Audit and Equipment Queries are administrative investigations into whether companies complied with federal vehicle safety requirements, such as reporting, recall and certification rules.
An open investigation is not a finding that a safety defect exists, and NHTSA can close one without a recall.
To see whether a specific vehicle has an open recall, enter its VIN at nhtsa.gov/recalls.
Free VIN check: decode a VIN to see its year, make and model.
Sources
NHTSA's investigation record for PE23-004
Investigation details come from NHTSA's investigations file, which try.vin imports once a day. The investigation types are described from the U.S. Department of Transportation Inspector General's May 2023 report on NHTSA's Office of Defects Investigation, NHTSA's petition rules (49 CFR Parts 552 and 557) and NHTSA's Office of Defects Investigation procedures. How try.vin reads NHTSA investigations.