On May 26, 2026, the National Highway Traffic Safety Administration's Office of Defects Investigation (ODI) opened a Preliminary Evaluation, numbered PE26004, into rear toe link separation on certain model year 2023-2024 Rivian R1S vehicles. According to the opening resume posted to NHTSA.gov, the agency acted after receiving two Vehicle Owner Questionnaires (VOQs) describing the left rear toe link separating from the vehicle while it was being driven. A toe link is a suspension component that fixes the rear wheel's alignment angle; if it separates, the wheel can lose its commanded orientation, which is why the agency's filing centers on the loss-of-control consequence rather than the part itself.

The record states that in both reported cases the failure produced an immediate loss of directional stability. NHTSA wrote that both owners reported the component separating while the vehicle was in motion and that the result was the vehicle moving across multiple travel lanes. The agency also recorded the physical signature shared by the two events: the bolt that holds the toe link together fractured in each case. The evidence ODI says it collected from the complaint vehicles included repair histories, onboard video, imagery of the damaged components, and a police accident report.

"Both VOQs report component separation while driving, causing the vehicles to swerve across multiple lanes of traffic. One incident resulted in a collision with an adjacent vehicle and roadside barrier."— NHTSA Office of Defects Investigation, PE26004 opening resume, source

What the two reports have in common, and where they differ

The opening resume is precise about the histories of the two vehicles, and it does not treat them as identical. NHTSA stated that the two vehicles with reported separation have different vehicle histories: one had received prior service, and the other had been involved in a previous collision. The agency noted that in both instances the vehicles operated for multiple months and thousands of miles with no apparent problems between that earlier service or collision and the failure that prompted the report. That detail matters to the scope of the investigation, because it frames the central question ODI says it is asking — whether a toe link joint can be left in a degraded but symptom-free state by foreseeable handling, only to fail much later under normal driving.

The filing situates the new probe against actions Rivian had already taken. NHTSA wrote that Rivian recognized the subject toe link joint's sensitivity to service procedures in March of 2025, when it updated its service procedures. The agency further stated that in January 2026, through recall 26V-003, Rivian extended the improved repair procedure to vehicles that had received toe link service before the March 2025 improvement. The Preliminary Evaluation does not displace that recall; rather, ODI's filing describes a probe that examines whether the population and the failure mode are fully addressed by the steps already disclosed.

The four questions ODI says it will pursue

NHTSA's opening resume lists the specific objectives of PE26004. The agency stated that it is opening the Preliminary Evaluation to assess the sensitivity of the rear toe link joint to foreseeable road and service conditions, to compare the physical failure evidence from the two VOQs to identify apparent similarities and potential differences, to evaluate Rivian's current toe link repair procedure, and to assess the in-field subject population's toe link conditions. Read together, those four items describe an inquiry that spans the component's engineering tolerance, the forensic pattern across the two failures, the adequacy of the repair instructions, and the condition of the parts still on the road.

The structure of the action is worth stating plainly for readers who follow the agency's process. A Preliminary Evaluation is the first formal investigative tier ODI uses. It is an information-gathering stage in which the agency typically requests data from the manufacturer and evaluates whether a safety defect trend exists. A PE can be closed without further action, or it can be upgraded to an Engineering Analysis, which is the deeper tier that more often precedes a recall decision. The agency's filing here does not assert that a defect exists across the fleet; it documents two reports, identifies a shared bolt-fracture signature, and states the questions it intends to answer.

The defect described is mechanical, not software, and that distinction is reflected in the record. The toe link is a load-bearing suspension joint, and the failure NHTSA recorded is a fractured bolt rather than a sensor or control-logic fault. The consequence the agency emphasizes — the wheel's alignment angle changing without driver input — is a stability and steering event. In one of the two reports, NHTSA wrote, the separation ended in a collision with an adjacent vehicle and a roadside barrier, which is the outcome that gives a suspension-geometry failure its safety weight: a sudden, uncommanded change in where a rear wheel points can move a vehicle laterally before a driver can correct.

NHTSA's filing identifies the manufacturer as Rivian and the subject population as certain model year 2023-2024 Rivian R1S vehicles, the company's three-row electric SUV. The agency's resume points readers to NHTSA.gov to review the ODI reports cited in the opening document by their Report Identification Numbers. As of the filing, PE26004 is recorded with an open status and a latest activity date of May 26, 2026; the agency has not announced a finding, a recall expansion, or a closure, and the docket states only the evidence collected and the questions to be examined. Readers tracking the matter can follow the docket directly on the agency's site, where ODI posts the manufacturer's responses and any subsequent change in the investigation's status.