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Bedford TM Lorry

(1974 to 1986)

The Bedford TM was a heavy goods vehicle constructed by Bedford Vehicles, the British arm of General Motors' commercial vehicle division, between 1974 and 1986. Up until the TM, Bedford had been building mostly low-specification short haul distribution trucks, such as the Bedford TK and KM. In view of the increasing popularity of high cab "luxury" cabs in the maximum weight long distance category, such as the Volvo F88, Scania 110 and Leyland Marathon, Bedford designed the TM as a competitor.

History

The TM was originally introduced in 1974, and was of a clean and modern design. A thorough update in 1982 left the appearance mostly untouched - perhaps to the detriment of sales of the mostly new model. Improvements included the new Detroit Diesel "Silver 92" engine, a new frame, many new engine and transmission options, and a variety of other updated fittings. The Fuller transmissions now received a new telescopic shift mechanism, allowing for a sealed cabin floor. The cab is counterbalanced so as to allow one-man tilting, while two front flaps allow access to check on vitals.

Powertrain

Through its lifespan, it was available with a Detroit Diesel two-stroke V8 and V6, the Bedford 500 turbo engine also known as the "8.2 Blue", or a Cummins L10 - coupled to either a Fuller or Spicer transmission, and a S.O.M.A. rear axle (dropped after the 1982 facelift). The Detroit engine (introduced in 1982) was not a successful choice in the UK. Because of its high-revving characteristics, it proved unpopular with drivers, who were used to slow revving, long stroke, UK diesels. It was also disliked by operators because of its poor fuel economy.

Bedford TM truck cab

Variants

Available as either an articulated tractor unit, or as a rigid, in either wide or narrow day and sleeper cabs, the TM was actually a highly competent vehicle, and over the years was a common sight with some of the larger UK operators. It offered new standards of comfort and refinement especially for a Bedford.

The TM 4-4 is an 8-tonne capacity 4x4 with tilt cab of which €40 million worth had been ordered by the British Ministry of Defence for delivery from 1980. It uses the Bedford six-cylinder 500 series engine 8198 cc.

TM 3800 plated for 38 tonnes GTW but limited to 32 tons in UK. It has the Cummins E-290 diesel developing 273bhp or the Detroit V-8 297 bhp diesel, A larger capacity TM 4200 for 42 tonnes G TW is also available, and other TMs are available with 2 or 3 axles as artics and rigids.

End of production

The model finally bowed out in 1986, with the collapse of its parent company; the UK military continues to use some four-wheel drive and six-wheel drive TMs but they are being replaced by more modern trucks produced by MAN SE

Late 1985 Bedford TM 4400 truck

Late 1985 Bedford TM

Technical

Bedford TM Technical details and specifications (1974-1986)

ENGINE :Detroit Diesel Type W V6
Type - 2-stroke, V6 4 overhead exhaust valves per cylinder operated by push-rods
Cooling system - Water pump, fan radiator (6/81b./in.')
Number of cylinders - 6 (dry,liners)
Firing order - 1L-3R-3L-2R-2L-2R-1R
idle speed - 500 r.p.m.; governed speed, 2100 r.p.m
Bore - 4.25in
Stroke - 5in
Cubic capacity - 426 in (6.97 litres)
Brake horse-power - 221 at 2100 r.p.m.
Torque (lb.ft.) - 593 at 1400 r.p.m.
Piston rings—number - 3 compression, 2 oil
Oil presure (lb./in.2) 50/70 1b./in. hot, at 1800 r.p.m. -
main bearings - 4 Thin shell, steel-backed, lead-bronze
Valve timing—inlet - Opens 124°ATDC; closes 236°ATDC
Valve timing—Exhaust -Opens 76°ATDC; closes 270°ATDC
Injector type - G.M. Allison Divn, type 71 (N—65), No. 5228900
TRANSMISSION V6

Type - Rear-wheel drive 4 x 2. 6 x 2 .6 x 4
Clutch - Rollway or spicer 14in. diam. twin plate
Gearbox (manual) - Fuller RTO-0/D, 9-speed
Drive shafts - Fully-floating, Eaton or Bedford axle
ENGINE :Detroit Diesel Type X V8
Type - 2-stroke, V8 4 overhead exhaust valves per cylinder operated by push-rods
Cooling system - Water pump, fan radiator (6/81b./in.')
Number of cylinders - 8 (dry,line)
Firing order - 1L-3R-3L-4R-4L-2R-2L-1R
idle speed - 500 r.p.m.; governed speed, 2100 r.p.m
Bore - 4.25in
Stroke - 5in
Cubic capacity - (9.31 litres)
Brake horse-power - 296 at 2100 r.p.m.
Torque (lb.ft.) - 784 at 1600 r.p.m
Piston rings—number - 3 compression, 2 oil
Oil presure (lb./in.2) - 50/70 1b./in. hot, at 1800 r.p.m.
Big-end bearings - 5 Thin shell, steel-backed, lead-bronze
Valve timing—inlet - Opens 124°ATDC; closes 236°ATDC
Valve timing—Exhaust -Opens 76°ATDC; closes 270°ATDC
Injector type - G.M. Allison Divn, type 71 (N—65), No. 5228900

TRANSMISSION V8
Type - Rear-wheel drive 4 x 2. 6 x 2 .6 x 4
Clutch - Rollway or spicer 14in. diam. twin plate
Gearbox (manual) - Spicer 10-speed O/D
Drive shafts - Fully-floating, Eaton or Bedford axle
SERVICE
BRAKES
Front - 5.5in. diam.
Rear - 5.5in. diam.
Handbrake - Spring brakes on all truck rear axles front axles on 4 X 2 Tractors
Power assistance - Clayton Dewandre, 3.line full-air
STEERING
Type - Burman recirculating ball, integral power assistance
SUSPENSION
Front
Single I-beam axle; semi-elliptic taper, leaf springs; hydraulic, telescopic shock absorbers
Spring length - 70in
Number of leaves - 2
Width of leaves - 2.95in.
Rear
Type - Semi-elliptic leaf springs ; shock-absorbers standard or optional according to model
Number of leaves - main 9 or 10
Width of leaves -2.95in.
ELECTRICAL
Battery - x2 24V. 128A.h; in-line engine,
Battery earth -Negative
Alternator -CAV AC5R-24; 31-8A. at 5000 r.p.m. -
Starter motor -Delco-Remy 40MT, type 200
© Motor car History

Service

Bedford TM Maintenance and Service Guide (1974-1986)

Detroit Diesel Type W V6 (6.97 litres)
Engine oil (total) - 34 pints
Engine oil (service) -30 pints
Gearbox - 15.5 pints
Differential - 16 to 24 pints according to model
Cooling system (total) - 88 pints
Fuel tank - 30-43 gallons
Detroit Diesel Type X V8 (9.31 litres)
Engine oil (total) - 42 pints
Engine oil (service) -38 pints
Gearbox - 34 pints
Differential - 16 to 24 pints according to model
Cooling system (total) - 104 pints
Fuel tank - 30-43 gallons
© Motor car History