Dodge / Ram
by Bill Horn-Andrews, Chrysler UK
Bill Horn-Andrews was Manager of Advanced Truck Chassis before becoming Chief Engineer Truck Development.
The Dodge 100 Series Commando was first developed by Commer Cars Ltd as a concept in 1965/66 and was intended as a replacement for the aging Commer VC and CE range of vehicles which ranged in weight from approximately 8 tons to 24 tons GVW/GCW.
ALSO SEE: 1969 Dodge commercial trucks (USA); Commer/Dodge 500 Series
The Commer - Dodge 100 Series truck was Chrysler’s (and Rootes’) most competitive truck in Europe, in its era. Chrysler UK’s Mike Kemp was the product planner for the project, whose genesis was the changing times in the United Kingdom’s auto industry.
Derek Harling wrote that Chrysler made their first investment in Rootes Group in 1965, partly by “nominally ‘merging’ Dodge and Commer operations:
“George Kozloff became Director of Product Planning and Engineering for the new Commercial Vehicle Division - the first joint Chrysler/Rootes department - and Tony Ainslie and I (both Chrysler people), with help from Jack Charipar from Chrysler International, initiated the Product Planning function.
“There were some initial plans for the new truck series within the old Commer Engineering department but the real planning, definition and approval of the 100 Commando Series happened within this new organization - little was left of the initial Commer-only plans. Mike Kemp came on board after George, Tony and I had moved elsewhere in Chrysler - and he and his team did an excellent job of controlling the development and launch of the Commando.”
Two years later, in 1967, Chrysler took control of Rootes
Group. The same trucks were sold as Commers, Dodges, and Karriers, but in the late 1960s and early
1970s, Chrysler standardized on Dodge in most areas. The Kew plant
was closed, and assembly of Dodge trucks was moved to the Commer
plant in Dunstable; some components were made in Luton.
The new range of trucks had to complement the newly introduced Dodge 500 Series. The ultimate aim was to produce a range of vehicles ranging in weight from 7.5 tons GVW up to 32 tons GCW. The upper weight of 32 tons being the maximum weight allowed in the UK at that time. This was to be achieved using three different cab widths and heights, but essentially using the same styling.
For the lower end of the weight range the vehicles would employ Perkins diesel engines. For the heavier models the Rootes Group TS3 and TS4 diesel engines and Cummins diesel engines were to be the favored power plant.
Barreiros, which made trucks and buses, became Chrysler Espana S.A. in 1970, and were sold to Peugeot (PSA) in 1980, becoming part of Automoviles Talbot S.A. In 1980, Talbot employed 15,500 people in the Villaverde complex near Madrid; 4,000 were employed by Dodge Trucks, which built trucks from 14,000 to 38,000 kg (gross weight). 5,500 of these were built in 1979, with 1,000 exported from Spain.
Three prototype vehicles were built in 1968 using the initial styling concept. This particular style had somewhat more shape than the final version, (it had a number of compound curved surfaces), and in the late 1960s this would have resulted in very expensive tooling bills. However, at the same time, the whole concept underwent a major review due to external influences. In 1965 Ford UK introduced the D Series which proved to be an effective competitor to both the Commer range of vehicles and the Bedford TK. What made Ford such an important factor was that it set new standards in both price and unladen weights. It was also streets ahead of their previous offering, the Ford Trader.
At the same time, the UK Government was introducing new legislation on power to weight ratios, stricter control of vehicle gross weights, axle loading and noise emissions. The noise legislation had a devastating effect on the future of Rootes Group’s own diesel engines, the TS3 and TS4. Neither engine could be economically suppressed to meet the new legislation. Later the situation was further complicated when Chrysler Corporation took full control of Rootes Group and the Spanish heavy truck manufacturer Barrieros. This effectively limited the 100 Series to 4x2 rigid vehicles of 7.5 tons to 16 tons GVW and 24/28 tons GCW tractor units. A 6x4, 24 ton tipper vehicle was introduced into the range in the late 1970s.
Following the concept review in 1968 the cab styling was completely changed taking on a more box-like appearance. This was basically the cab style that went into final production.
At one stage an investigation was carried out to determine what the implications would be if the range were to be marketed in the USA. However, major changes to the design would have to have been made in order to meet the FMVS requirements. These changes made the project unfeasible on cost grounds.
During the design phase of the Commando the major concern was the power plant. At the lower end of the range Perkins diesel engines were employed namely:
Although the Perkins diesel engines were reliable and adequate for their intended tasks they were not particularly well known, at that time, in Europe. This was seen as a problem in as much that the European Common Market was becoming a reality and it was the intention to export the 100 Series into continental Europe. To this end several different engine manufacturers were investigated. The first of these was Mercedes Benz. The engine considered was the OM352 as it was well known in Europe. This was intended to be the premium engine offering. Following a full development programme this engine was put into production.
Two Mitsubishi six cylinder diesel engines were tested in two prototype vehicles. Although they produced sufficient power they were high revving engines and proved to be unsuitable for the intended application and the test programme for these engines was suspended.
The other engine considered was a MAN-DEUTZ air cooled diesel one. This project did not get beyond the feasibility stage due to major installation difficulties.
At various times during the programme Caterpillar, Detroit Diesel and the Italian company OM were all considered as engine suppliers but were all rejected. The final engine line was the Perkins engines and the Mercedes Benz OM 352.
The choice of transmission system was relatively straight forward. The Rootes Group had developed a range of synchromesh gearboxes for the VC and CE models during the 1960s which had proven to robust and reliable. These units, with minor modifications, were incorporated into the vehicles; the four speed transmission being used in vehicles up to 12 tons GVW and the five and six speed boxes being used above this weight.
The rear axles were a mixture of Rootes Groups’ own hypoid design and Eaton’s single and two speed axles.
The chassis was of a conventional ladder frame construction although it used higher UTS steels than those previously employed. The front and rear suspensions were of a lightweight multi-leaf design using minimum leaf helper springs and telescopic shock absorbers. Single leaf suspension was investigated during the concept stage but was rejected on the grounds that it was unproven technology.
For vehicles up to 13 tons GVW the brakes were air/hydraulic supplied by A P Lockheed. Above this weight Girling supplied full air S cam brakes.
Initially a completely new design of steering gear was employed on the lower weight vehicles but this proved to be unreliable so the more conventional steering gears supplied by Cam Gears were used. Power steering was achieved by using a power steering ram.
The test programme was straightforward apart from the problems caused by the new noise legislation. This resulted in a protracted test schedule involving the use of noise absorbing side shields and under trays. This, in turn, led to difficulties achieving the engine cooling targets. As computer predictions were in the early stages of development, these problems had to be overcome by using a series of tests that were based on trial and error and experience until acceptable compromises were found.
A press release issued in 1974 by Chrysler International, Bowater House, 68 Knightsbridge, London provided these specifications. They claimed seven 4x2 rigids, ranging from 7,500 to 16,257 kg in gross vehicle weight, with three to five wheelbases depending on capacity (3 wheelbases up to 9,856 kg; four from 11,380 to 14,733; and five for 16,257 kg). There was also an 18,289-kg GCW tractor.
Engines were as listed earlier: Perkins 4.236, 6.354, and T6.354; along with the Mercedes OM352 six-cylinder in-line diesel and “Chrysler LA318-3 V8 petrol.” Gearboxes were a four-speed, five-speed, and six-speed manual, all with synchromesh; only the six-speed had overdrive. The four-cylinder diesel had an 11 inch clutch; the six-cylinder had a 13 inch clutch; the turbo diesel had a 14 inch clutch; and the gasoline engine, a 12.3 inch clutch.
Single-speed rear axles were the Chrysler AX2, AX3, AX4, and AX5, ranging from 5.8 to 9.15 tons in capacity; The Eaton 18100 and 18120 were also available, with 10.16 ton capacities. For two-speed axles, Eaton models provided 7.73 to 10.16 tons of capacity.
A tilt cab was standard, a fixed cab optional, with three or four door crew cabs optional except on tippers. Wheels were 16 and 20 inches, with cross-ply and radial tires. Brakes were air-hydraulic (dual line) up to 14.7 tons, full-air standard on 16.3 ton (optional on 14.7), with air-hydraulic on tractors. A 12 volt electrical system was standard, with 24 volts optional.
The 100 Series was in production for approximately 15 years and saw service in most areas of the world. During this time the 100 Series was branded as Commer, Dodge, De Soto, Fargo and Renault. In the mid to late 1970s a Mark 2 version was launched which was essentially a series of engine upgrades and minor refinements to the chassis and cab.
The occasional model can still be seen in service on the roads of the UK today and may well be in service elsewhere in the world.
2013-14 Ram Chassis Cabs
Aero-tuning the Dodge NASCAR trucks
All Mopar Car and Truck News
Chrysler 300 Letter Cars
The Engine Cleanup Committee