DETROIT (Reuters) - Toyota Motor Corp is recalling about 780,000 crossovers and hybrid sedans in the United States for a second time to repair a suspension defect that was not properly fixed last year, a Toyota spokeswoman said on Monday.

The Japanese automaker first recalled the 2006 through 2011 RAV4 crossover and the 2010 Lexus HS250 hybrid sedan in August 2012 to prevent the rear suspension arm from wobbling, which could cause rust and lead to a crash.

But Toyota found that the nuts used to adjust the rear wheel alignment may not have been properly tightened, according to documents posted online by the National Highway Traffic Safety Administration.

As a result, Toyota must take the rare step of recalling those models again. Under the new repair, Toyota will seal the rear lower suspension arms with an epoxy to prevent corrosion.

Due to a limited availability of parts, Toyota will launch the recall in stages until February 2014. Toyota began fixing 2006-2008 model year vehicles last month in the Boston area. It will inspect 2009-2011 models nationwide in mid-February.

As of the end of June, Toyota had inspected and fixed 20,400 vehicles. Nearly 482,000 were inspected and found not to need a fix, according to U.S. auto safety regulators.

(Reporting by Deepa Seetharaman; editing by Matthew Lewis)