H2 steering knuckle deemed safe

[h2co-pilot]

Safety probe clears Hummer

U.S. panel finds no defect in a steering part in H2 model.

By Andrew McIntosh - Bee Staff Writer

Published 12:00 am PDT Friday, May 11, 2007
Story appeared in MAIN NEWS section, Page A1


Saying they discovered no safety-related defect, federal highway safety officials have closed a two-year probe into a Hummer H2 steering part that fractured and caused wheels to fall off some of the mighty vehicles.

The National Highway Traffic Safety Administration wrapped up its investigation into the H2 part -- called a steering knuckle -- on April 30, saying it found nothing to suggest H2 knuckles are failing from ordinary use.

A three-member NHTSA panel suggested that impacts appear to be the cause for eight of 15 H2 knuckle failures and crashes studied.

The panel's report also notes that the seven other steering knuckle-related Hummer H2 crashes examined involved Hummers not known to have "struck any other vehicle."

The NHTSA cautioned that its decision to close the investigation does not constitute a finding that no safety-related defect exists with the H2 steering knuckle and that it reserves the right to take further action if warranted.

Steering knuckles hold the vehicle's steering arms in place near the SUV's front tires.

Alan Adler, a product safety spokesman for General Motors, which makes the Hummer, said the automaker was pleased that no defect was found. "Presumptive media reporting surrounding this investigation unfairly suggested a product defect," Adler said.

"GM contended early in the investigation that the reported knuckle fractures were occurring only in crashes and other impacts."

The Bee reported last July that the NHTSA was investigating more than two dozen cases in which owners of Hummer H2s complained that wheels either fell off or their front suspension collapsed after the steering knuckle fractured and failed.

Among them was The Bee's own auto editor, who had encountered the problem during a test drive. Also on the list was Jonathan Barksdale of Pennsylvania, who said his steering knuckle failed and wheel fell off while he drove near his home in 2003. GM later bought his vehicle back.

The NHTSA report states H2 steering knuckles can become overloaded and fracture when their tires or wheels strike large, heavy objects at speeds as low as 5 miles per hour.

It added that it is "quite possible" that some H2 drivers would not notice they had hit a curb or other object because of their SUV's high, long and wide hood.

Such impacts directly involving the wheel or tire can snap the metal knuckle, causing ball joints and front wheels to separate and the suspension to collapse, the NHTSA report said.

Auto industry analysts maintain that a Hummer, marketed as a rugged off-road vehicle, should be able to withstand hitting a curb. One automobile claims expert, Charlie Barone, who represented Barksdale, said that his client's steering knuckle failure after driving only 381 miles pointed to a manufacturing defect "just waiting to happen."

The federal report said the number of knuckle-related failures linked to crashes has dropped significantly since June 2003, when GM and its suppliers redesigned and strengthened the H2 knuckle and removed the older part from production and sale.

There were 15 crashes allegedly caused by fractured knuckles in H2s built between March 2002 and June 2003, compared to just five since then, the agency said.

The NHTSA also said GM increased the H2's recommended tire pressure to 44 pounds per square inch from 35 PSI for fuel economy improvements.
The change, the agency noted, also diminished friction between tires and road and reduced stress on the SUV's steering system.

The NHTSA said it found the newer H2 steering knuckle was "significantly more resistant to failure" than the original part, but added that tests of the older part did not prove that the earlier design was inadequate either.

The April 30 NHTSA report said the agency had not received any new reports of steering knuckle failures since November.
Yet two H2 owners have contacted The Bee since then, after the wheels fell off their Hummer H2s.

One, a New York service station owner, said he had called the NHTSA to report his problem but was told the investigation was closed.
The NHTSA declined to comment, citing privacy restrictions.

http://www.sacbee.com/101/story/175647.html

[hummer.dad]

Since when did they recommed 44psi for the tires? My door sticker says 37. Interesting statement. My dealer has never filled above 37 either. I have an '06 SUT.

[Agriv8r]

example of writing before researching....

[johndjmix1]

i run 60 psi......for milage reasons.

--John