GM is throwing more cash on the hood of its full-size trucks.

General Motors has decided to offer deeper discounts on its full-size pickup trucks to help clear out its remaining 2013 models. GM's truck inventory has ballooned to pre-bankruptcy levels in recent months, threatening the launch of its all-new range of 2014 pickup models, expected out next year.

GM announced on Friday that its full-size pickup trucks - the Chevrolet Silverado and GMC Sierra - will be eligible for up to $2,000 cash back until January 2. The offer is good for both 2012 and 2013 models.

Those incentives are in addition to the $1,000 in bonus cash GM is already offering on the trucks, according to Automotive News.

GM's truck inventory has swollen in recent months due to the timing of its 2013 model year rollout, which was about 45-days sooner than usual. Whereas GM's main competitors, Ford and Chrysler, have been pushing discounted 2012 models, GM dealers have been forced to peddle higher-priced 2013 models. As a result, GM's truck inventory now stands at 130-days, or about 30-days higher than ideal.

GM will unveil all-new versions of its Silverado and Sierra at the Detroit auto show next month and needs to clear out its inventory before then. The 2014 model year trucks are expected to hit the market mid-year, so it's possible GM could offer another round of incentives just prior to that on-sale date.