03-5137. Denial of Motor Vehicle Defect Petition, DP02-010

AGENCY:

National Highway Traffic Safety Administration (NHTSA), Transportation.

ACTION:

Denial of petition for a defect recall.

SUMMARY:

This notice sets forth the reasons for the denial of a petition submitted to NHTSA under 49 U.S.C. 30162, requesting that the agency initiate an investigation of model year (MY) 2000 and 2001 Suzuki GSX-R750 motorcycles to address an alleged safety-related defect. The petition is identified as DP02-010.

FOR FURTHER INFORMATION CONTACT:

Mr. Leo Yon, Office of Defects Investigation (ODI), NHTSA, 400 Seventh Street, SW., Washington, DC 20590. Telephone: [phone].

SUPPLEMENTARY INFORMATION:

Mr. Scott M. Shannon of Clearwater, Florida, submitted a petition to NHTSA dated October 8, 2002, requesting that NHTSA open a defect investigation on MY 2000 and 2001 Suzuki GSX-R750 motorcycles (the subject R models). The petition alleges that the motorcycles' 6-speed manual transmission contains a safety-related defect, which causes the vehicle to slip or shudder while under load in second gear.

The four cylinder 750cc Suzuki GS series motorcycles, for the years in question, were sold as two designated models: GSX-750 and GSX-R750. Approximately three times as many subject R models were sold in the U.S. as compared to the base model. Prior to MY 2000, the two models shared the same transmission components. For MY 2000, the R model received several design changes to enhance the motorcycle's performance. These changes include, but are not limited to, a revised overall final drive ratio through the use of a new transmission gear set. Other transmission modifications were also introduced in an effort to improve the motorcycle's perceived shift quality and feel.

To evaluate the petition, an information request was sent to the manufacturer, American Suzuki Motor Corporation (Suzuki), in November 2002. In its response, Suzuki submitted data for both models for MYs 1999 through 2001. The total population of the subject R models is 11,551 motorcycles. Following the introduction of the MY 2000 R model, Suzuki received a significant increase in the number of consumer complaints relating to the motorcycle's transmission. Suzuki reported that it received 248 consumer complaints about the subject R models where the key words “second gear” or “shifting” were found in the description field. This compares to 7 similarly-derived consumer complaints for both MY 1999 models. A corresponding increase occurred in warranty-related claims. Suzuki reported that, according to claims submitted by dealers on transmission parts, there were 439 claims attributed to the subject R models. This compares to 7 for both MY 1999 models. Field reports and calls by dealers to Suzuki's technical hotline for advice on this topic accounted for 492 contacts for the subject R models, compared to 10 for both MY 1999 models.

Suzuki reported only one claim of an injury that may have been caused by this condition in the subject R models. Five Suzuki technical hotline reports allege a crash that may, or may not, relate to the alleged defect. Suzuki stated that there is insufficient information concerning these alleged incidents to allow it to assess these reported incidents. Suzuki has no lawsuits or subrogation claims pertaining to the alleged defect regarding the MY 2000-2001 R model motorcycles.

NHTSA has received 30 “transmission” complaints involving the MY 2000 R models, with one injury allegation and one crash allegation.

To address consumer complaints about this condition, Suzuki redesigned the second driven gear for the R model. In November 2000, a newly-developed second driven gear was introduced as a running change to the MY 2001 R model and released as the recommended service part for all subject motorcycles. A technical training video was released to Suzuki dealers to help their mechanics diagnose the symptoms before disassembling the transmission. A copy of this tape was supplied with Suzuki's reply to ODI's information request.

Suzuki's Quality Assurance group examined several warranty return parts for mechanical integrity, noting that several displayed signs of abuse consistent with “incomplete or abusive shifting practices.” Suzuki alleged that these practices will produce high impact shock loads between the gears' engagement surfaces, leading to localized deformation. Eventually, the deformation helps to create a force between the two gears, in this case second and sixth, pushing them apart. If the magnitude of the separating force between the gears exceeds the force generated by the shifting mechanism to hold them together, the two momentarily disconnect, and then are forced back together by the shifting mechanism. This momentary disconnect-reconnect as the motorcycle is accelerated gives the operator a slipping or popping sensation as the transmission delivers torque to the rear wheel. Under rapid acceleration, the operator can experience a quick, hesitation-like feeling when second gear momentarily disengages, accompanied by a change in the pitch of the sound generated by the engine. Left unattended, the slippage can increase in frequency and duration.

To reproduce and demonstrate the failure consequences to ODI, Suzuki prepared one subject motorcycle with parts intended to represent worst-case conditions on the engagement surfaces of the second gear. Additional instrumentation was installed on the shifting mechanism to record the resultant forces and the momentary disconnect of the second gear. Normal operation of the motorcycle, accelerating through a series of turns and straight roadways, was digitally taped (video) to allow analysis of the condition and its consequences, both from an observer's perspective and that of the operator. Review of the video clips did not identify an increased risk to safety or a loss of vehicle control.

Based on this analysis, it is unlikely that NHTSA would issue an order for the notification and remedy of a safety-related defect in the subject vehicles at the conclusion of the investigation requested in the petition. Therefore, in view of the need to allocate and prioritize NHTSA's limited resources to best accomplish the agency's safety mission, your petition is denied.

Authority: 49 U.S.C. 30162(d); delegations of authority at CFR 1.50 and 501.8

Issued on: February 26, 2003.

Kenneth N. Weinstein,

Associate Administrator for Enforcement.