In 1924, William Pigott sold control of the Company to American Car and Foundry Company. During the Depression of 1929, business declined and the Renton plant fell into disrepair.

Paul Pigott, son of the founder, acquired a major interest in the Company from American Car in 1934. Under his leadership, the Company expanded its products and introduced the Carco line of power winches for use on crawler tractors in the logging industry. This product line later became the basis for PACCAR's Winch Division which now includes Braden, Carco and Gearmatic.

In 1941, America went to war, and the Company's Renton plant built Sherman Tanks and tank recovery vehicles for the military. Pacific Car and Foundry also constructed dry docks and steel tugboats during the conflict.

The Company entered the heavy-duty truck market in 1945 with its first major acquisition, Kenworth Motor Truck Company of Seattle. Pacific Car and Foundry greatly expanded its heavy-duty truck capability with the purchase Peterbilt Motors Company in 1958. That same year, the acquisition of Dart Truck Company permitted its entry into the entirely new market of mining vehicles.

The Company's Structural Steel Division fabricated the steel for the construction of the Space Needle for the 1962 Seattle World's Fair. Later, it played a major part in the construction of Grand Coulee's third powerhouse as well as New York's World Trade Center.

In 1960, PACCAR became an international truck manufacturer. Kenworth moved into Mexico with 49 percent participation in an affiliate company, Kenworth Mexicana S.A. de C.V., and in 1966 PACCAR entered the Australian truck market with the establishment of a Kenworth Truck assembly plant near Melbourne.

Also in 1960, Carco Acceptance Corporation, currently PACCAR Financial Corp. , was launched to facilitate domestic sales of trucks.

In 1967 the Dynacraft division was formed to provide belts, hoses, adapters, and other accessories for Kenworth and Peterbilt truck plants.

Believing "Pacific Car and Foundry Company" no longer accurately reflected the Company's products and activities, directors and shareholders voted to adopt PACCAR Inc (no punctuation) as its new name in 1972. Pacific Car and Foundry Company, located in the original Renton facility, became a division.

In 1973, two major divisions of PACCAR were founded. PACCAR International Inc., with headquarters in Bellevue, Washington, was formed to consolidate the sales and service of company products abroad, and PACCAR Parts Division was established in Renton to supply aftermarket parts sales.

PACCAR Leasing Corporation was formed in 1980 to offer full-service leasing and rental programs through PACCAR's dealer network. A year later, PACCAR became an European truck manufacturer with the acquisition of Foden Trucks in Sandbach, U.K.

PACCAR's new Technical Center opened in July of 1982. Located approximately 65 miles north of Seattle, the multimillion-dollar center underscored the Company's commitment to technical excellence, quality and value in the products it manufactures.

In 1986, PACCAR signed a merger agreement with Trico Industries, Inc., and became a recognized world leader in manufacturing oil field pumps and accessories. In December 1997 Trico was sold to EVI of Houston.

In 1987, PACCAR acquired Washington-based Al's Auto Supply, an aftermarket retailer and wholesale distributor of auto parts and accessories. In 1988, PACCAR increased its subsidiary PACCAR Automotive, Inc. when it purchased Grand Auto, Inc., a California-based retailer of auto parts and accessories. In October 1999, PACCAR Automotive was sold to CSK Auto, Inc.

PACCAR solidified its place in the Mexican heavy-duty truck market by purchasing the remaining portion of its Mexican Operation, VILPAC, S.A. in 1995.

The acquisition of DAF Trucks N.V. in 1996 and Leyland Trucks in 1998 solidified PACCAR's position as one of the major truck manufacturers in the world. DAF Trucks is a Netherlands based truck company with production facilities in Eindhoven, the Netherlands and Westerlo, Belgium. Leyland manufactures trucks in the 6-18 ton commercial segment at its plant in Lancashire, England.

In 1969, 28 acres of land were purchased at suburban Bayswater - 30 kms east of Melbourne for Kenworth Australia. Construction plans were drawn up and by 1970, the 56,000 sq. ft factory and office complex was completed to produce trucks initially on a CKD (Completely Knocked Down) basis. Throughout Kenworth Australia's 30 year history in Australia, it has become a major manufacturing force in the Australian, New Zealand and Papua New Guinea markets.

Today, PACCAR Inc is a worldwide manufacturer of light-, medium- and heavy-duty trucks under the Kenworth, Peterbilt, DAF, Leyland and Foden nameplates. It also provides financial services and distributes truck parts related to its principal business. In addition, the Bellevue, Washington-based company manufactures industrial winches.