DETROIT, April 11 (Reuters) - Ford said Thursday it will begin shipping to North American dealers 144,000 of its redesigned F-150 and Ranger pickup trucks that it built but held back until now in an effort to head off quality problems.

Ford said it also is restarting shipments of F-150 Lightning electric trucks which it had halted in February.

The wave of large F-150s, Ford's best-selling model, and mid-size Ranger trucks will be critical for Ford to hit its 2024 pre-tax profit target of $10 billion to $12 billion. The automaker reaffirmed that target last month.

The delay in sending the trucks to dealers could hit the automaker's first quarter numbers due April 24.

Ford Chief Financial Officer John Lawler told investors last month the company had 60,000 F-150s in stock it expected to ship in the current quarter.

The automaker first tried a go-slow approach to vehicle launches last year at its Kentucky Truck complex that builds Super Duty pickups and Navigator large SUVs. Ford paid out nearly $4.8 billion to cover warranty repairs in 2023, according to its annual report.

In the case of the redesigned F-150s, Ford engineers analyzing data from trucks held in stock discovered that certain electronic components did not shut off, or were using more power than expected, Ford said. "Engineers updated the problematic software before any trucks left the plant," the company said in a statement. (Reporting By Joe White, Editing by Nick Zieminski)