A quarter earlier than expected, Oshkosh Truck Corp. [OSK] on Monday afternoon said the Family of Medium Tactical Vehicles (FMTV) truck program will turn a profit in the current quarter, three months earlier than it previously projected.

That news was contained in a handful of filings with the Securities and Exchange Commission (SEC) that also included additional details from activist investor Carl Icahn’s firm saying why its minority slate of candidates should be elected to the Oshkosh board of directors at the company’s annual shareholders’ meeting on Jan. 27.

Last month and then again last week Icahn Associates presented and discussed its six nominees for the 13-member Oshkosh board, providing a general outline of why it says the diversified truck maker needs new people on the board to help the struggling company “effect positive change (Defense Daily, Jan. 9).” Icahn owns 10 percent of Oshkosh’s stock, making him their largest shareholder.

On Monday, Icahn repeated his previous concerns about Oshkosh’s negative shareholder returns the past four years, adding that it is in the bottom 15 percent of stock performers the past five years, and rejected management’s argument that it is outperforming key competitors.

“Commercial businesses that compete with Oshkosh core businesses are substantially outperforming despite facing similar headwinds of reduced municipal spending and a weak economy,” Icahn says in a slide presentation contained in one of Oshkosh’s SEC filings.

Icahn also says that Oshkosh overpaid in 2006 for the access equipment company JLG, saying it should consider selling the unit. He also says that the company’s military truck business is underperforming, noting that operating income from the unit is expected to be about $124 million in 2013 on $2.3 billion in sales, slightly lower income than in 2004 on $775 million in sales.

Icahn says that Oshkosh’s defense business is suffering from “margin underperformance.”

In its own presentation released through the SEC on Monday, Oshkosh says its total shareholder return since 1996 is nearly 19 percent, more than three times the growth of the S&P 500 index and that its total shareholder return the past three years was 45 percent compounded annually.

The company also said that JLG is “integral” to its business and contributed to its winning the FMTV contract and another multi-billion dollar military vehicle contract, the M-ATV, or Mine Resistant Ambush Protected-All Terrain Vehicle.

Oshkosh will report its first quarter FY ’12 results on Jan. 31. In the SEC filings, the company says that it is achieving improved vehicle performance and quality. Oshkosh also says the sooner than expected FMTV profit “should not be construed to reflect expected earnings for the Company’s defense segment or the Company as a whole for the first quarter of fiscal 2012.”

Oshkosh beat incumbent Britain’s BAE Systems and another competitor, Navistar [NAV], for the Army’s FMTV award in August 2009, although subsequent protests and a revaluation of bids resulted in a final award to the company in February 2010. The first trucks under the new contract were delivered in January 2011. The Army plans to buy 18,700 FMTV trucks and 8,000 trailers under the five-year contract.