The Chrysler Royal AP1 Plainsman was the station wagon version of Chrysler Australia’s first locally developed full-size passenger car. Introduced in the late 1950s, the Plainsman combined the strong mechanical components of the Chrysler Royal sedan with a spacious wagon body designed for families, touring and commercial use.
Produced by Chrysler Australia Limited at Keswick in South Australia, the Plainsman offered generous luggage capacity, durable interior materials and a strong chassis suited to the long distances and varied road conditions found throughout Australia.
The following factory specifications outline the key mechanical and dimensional features of the Chrysler Royal AP1 Plainsman wagon.
Dimensions
Wheelbase: 115 inches
Overall length: 200 7/16 inches
Maximum width across bumpers: 73¼ inches
Overall height: 64 inches
Kerb weight:
Standard transmission: 1 ton 14 cwt
With PowerFlite automatic transmission: 1 ton 15 cwt
With automatic overdrive: 1 ton 15 cwt 1 qr
Engine
The Plainsman wagon used Chrysler’s reliable six-cylinder L-head (side valve) engine, designed for smooth operation and strong low-speed torque.
Number of cylinders: 6
Displacement: 250.6 cubic inches
Bore: 3 7/16 inches
Stroke: 4 inches
Taxable horsepower: 28.3
Maximum horsepower: 117 hp at 3,600 RPM
Maximum torque: 205 lb-ft at 1,400 RPM
Compression ratio: 7.25:1
Main bearings: 4
Piston rings: 2 compression rings and 2 oil control rings
Braking System
The Chrysler Royal Plainsman used hydraulic self-equalising internal expanding brakes.
Each front wheel used an individual hydraulic cylinder to provide balanced braking performance.
Drum diameter: 10 inches
Total lining contact area: 150 square inches
The hand brake operated on the rear service brakes for manual transmission models and on the transmission brake drum for PowerFlite automatic models.
Steering
Steering used a direct double tie-rod gear system with worm and three-tooth roller mechanism.
Steering ratio: 18.2 to 1
Optional Power Steering
Full-time hydraulic power steering was available as special equipment. The system used a rotary-type hydraulic pump mounted at the rear of the generator, supplying pressure to assist the steering linkage.
Transmission Options
The Plainsman wagon was available with several transmission choices.
Conventional Transmission
Three-speed manual gearbox with all helical gears.
Synchromesh on second and third gears.
Gear ratios:
3rd: 1.00 to 1
2nd: 1.83 to 1
1st: 2.57 to 1
Reverse: 3.49 to 1
Automatic Overdrive
Automatic overdrive was available as special equipment with the manual transmission.
Overdrive ratio: 0.7 to 1
Minimum engagement speed: 25 mph
Electrical control with manual lock-out switch.
PowerFlite Automatic Transmission
Push-button PowerFlite automatic transmission was also available as optional equipment.
This two-speed automatic used a torque converter coupled to a planetary gearset.
Gear ratios:
Low range: 1.72 to 1
Direct drive: 1.00 to 1
Reverse: 2.39 to 1
Rear axle ratio: 3.54 to 1
Rear Axle
Semi-floating hypoid axle with two-pinion differential.
One-piece forged housing provided uniform strength across the axle assembly.
Rear axle ratios:
Standard transmission: 3.9 to 1
Overdrive models: 4.1 to 1
PowerFlite automatic models: 3.54 to 1
Wheels and Tyres
Steel disc wheels with drop-centre rims.
Wheel size: 15 x 4.5K
Standard tyres: 6.70 x 15
Five tyres supplied including spare.
Optional equipment included white sidewall tyres.
Equipment and Interior
The Plainsman wagon featured durable interior materials designed for easy cleaning and long service life.
Interior features included:
Safety-button rear door locks
Rubber padded arm rests on all doors
Thick foam seat cushioning
Vinyl trim materials designed for durability
Dual air-tone horns
Cigar lighter
Instrument panel ash trays
Wrap-around bumpers
Comprehensive tool kit and tyre pump
Dual sun visors
The body was sealed against dust and rain and insulated to provide a quieter ride during long-distance travel.
Chrysler Royal Plainsman
The Plainsman wagon provided Chrysler Royal buyers with a versatile vehicle capable of carrying passengers and cargo while maintaining the strong performance and durability associated with the Royal series.
With its robust chassis, large interior space and proven Chrysler mechanical components, the Plainsman became one of the most practical station wagons available in Australia during the late 1950s.
Complete technical specifications, engine servicing procedures and repair information for Chrysler Royal AP1 models can be found in the Chrysler Royal workshop manual available from Car Manuals Direct.
