Honda Motor Company (Japan) announced a massive recall, involving almost 183,000 of its popular Civics built across 2006 and 2007 model years.

In these Civics, the wheel bearings can become contaminated and fail, presenting a potential wheel-off situation.

While the popular media has characterized the recall as related to faulty bearings, in fact the bearing failure is a secondary effect.

The real culprit in the bearing failures is improper sealing of the wheel speed sensor, potentially allowing contamination and corrosion to develop in the rear wheel bearings.

The affected Civics, both sedans and coupes, were built between March 24, 2005 and February 8, 2007. The cars were sold both in the U.S. and Canada.

For this recall, the NHTSA Campaign is 07V-399000 [overview] [details]. The Honda recall is reference Q56.

Honda's recall states:

On certain vehicles, the wheel speed sensor housing uses an O-ring seal to prevent leakage to or from the wheel bearing. If assembled improperly, the O-ring may not seal properly, allowing water to enter the wheel bearing and eventually cause damage to the bearing, especially in areas where use of road salts is prevalent.

If the driver continues to drive with the condition, it is possible for the wheel bearing to become loose, which could cause the bearing to overheat and fail.

This could cause a wheel to fall off the vehicle, possibly resulting in a crash.

Dealers will inspect the ABS sensors and wheel bearings for damaged parts and replace them free of charge.

The recall is expected to begin on or about September 17, 2007. Owners may contact Honda at 1-800-999-1009.

Aged, leaking, and improperly installed ABS and speed sensors have been a recurring problem affecting wheel bearing service life and prompting recalls. GM's wheel bearing hub assembly units with integral wheel speed sensors were the first to be blamed for regular contamination-related failures, with Ford and DaimlerChrysler also suffering issues in the past several years.

Honda estimates only 5% of the Civics being recalled actually have improperly installed O-rings. Unfortunately, there is no method to determine what 5%.

Involved in the recall are:

Civic coupe	MY 2006	2HGFG12636H500009 - 12816H584624
	build	March 24, 2005 through September 1, 2006
	MY 2006	2HGFG21306H700004 - 21516H713846
	build	March 29, 2005 through September 1, 2006
Civic sedan	MY 2006	2HGFA15506H500005 - 16856H528911
	build	May 25, 2005 through September 1, 2006
Civic coupe	MY 2007	2HGFG12677H500001 - 12847H539744
	build	July 25, 2006 through February 8, 2007
	MY 2007	2HGFG21517H700001 - 21527H706051
	build	June 6, 2006 through February 8, 2007
Civic sedan	MY 2007	2HGFA16807H500001 - 16837H502258
	build	May 31, 2006 through February 8, 2007
	MY 2007	2HGFA55557H700001 - 55557H707417
	build	May 31, 2006 through February 8, 2007

Honda began its investigation earlier this year after two wheel-offs occurred in Canada, one during towing and another during dealer service.

The recall will formally begin as of September 17, 2007.