A line of brand new Tempo G1200's at Vidal & Sohn's Tempo factory in Hamburg.
This is my English translation of a 1941 Tempo G1200 user manual from Finland. Thanks again to the Finnish National Archives for making these documents available.
The Vidal & Sohns Tempo G1200 All Terrain-wagon is a specially designed vehicle, whose independent suspension, light weight and remarkably powerful engines make it possible to traverse ground which cannot be covered by other wheeled vehicles. It is clear, however, that driving skill is crucial for the vehicle’s off-road use, and for this reason it is necessary that every driver becomes familiar with the following instructions before actually driving the truck off-road. This user manual also covers the technical details, care and maintenance procedures that must be observed for the all-terrain wagon.
The VIDAL all-terrain wagon can meet the intended tasks only if all of its parts and equipment have been treated in accordance with the instructions and it is therefore essential these instructions strictly observed.
Components and their functions
The VIDAL all-terrain wagon has a simple structure. Both engines are attached through bores in the tube chassis. While the back of the motor is securely attached to the chassis tube, the front motor is able to move around the shaft to a large degree. Mobility is thereby achieved within the substructure, with the result that all four wheels are able to maintain contact and driving capacity on almost any terrain (see drawing No i)
Each motor operates completely independently since each engine is fitted with a dynastarter and generator, a gearbox and differential, and all necessary fittings, such as carburetor, exhaust pipe, ignition switch, etc. The engines are two-stroke and lubricated by the fuel-oil mixture, which for the first 800 km should be fed a mixture of 20:1 (20 gallons of fuel and 1 liter of SAE 40 oil), and later at a ratio of 25:1. Fuel and oil must be mixed in a clean container before being poured into the fuel tank – please ensure that only good quality fuel and lubricants are used. When mixing the fuel-oil, care must be taken to avoid dirt and water contaminating the mixture.
The more carefully the engine is driven at the beginning, the better the engine will work later and the longer they will last. Therefore, during the first 800 - 1,000 miles, the truck should not be run a higher speed than 30 km/h. Normal driving (after running in) is subject to the following maximum speeds:
1 gear 15 km
2 gear 25 km
3 gear 35 km
4 gear 65 km
The starter motors are combined with the generators (German: lichtmachines) that are connected directly to the engines. Apart from the regular cleaning of carbon (every 2000-3000 km of driving), and adjustment of the carbon brushes according to the level of wear, the generators and starter motors do not need any special treatment. If repairs are required, these should only be undertaken by a trained professional, preferably by a qualified Bosch technician.
The starter motors may be engaged separately. To start, press the corresponding starter button in the driver’s cabin (the front motor ignition switch is on the left, the rear motor ignition switch is on the right).
Gearbox maintenance is mainly limited to ensuring the correct levels and consistency of oil is maintained. In order to avoid shifting problems the gearbox oil should be checked every 14 days when in use.
The most suitable lubrication in summer is a quality SAE 160 oil. In winter, a 1:1 blended ration of SAE 160 and SAE 40 oil is recommended.
To fill the gearbox, open the oil filler hole and unscrew the oil level hole at the front of the gearbox. Top up the oil through the filler hole until it reaches the oil level hole, then reseal (Figure No 2).
In order to minimize wear when driving, ensure the clutch is engaged and disengaged cleanly and the gear changes are carried out in a calm and proper manner.
The different gear shifter positions are described in the attached drawing (No 3). To the rear of the gear shifters is a hand activated lever to lock the two gear shifters together. Activating the lever all enables the gear shifting for both engines to be performed at the same time. By deactivating the lever, either gearbox may be operated independently. The forward gear lever operates the front engine while the rearward gear lever operates the rear engine. Do not operate the independent engines in opposition to each other.
Each engine is connected to the gearbox through its own clutch, which enables the engine to be engaged and disengaged. The left hand pedal in front of the driver's seat operates both the front and rear clutches at the same time. The clutch pedal must have about 5mm of play at all times. The clutch cable is susceptible to strain and if it becomes too taut or slack, the clutch may experience premature wear and operational uncertainty. The same effect can also be caused by the driver riding the clutch, even lightly, or trying to overcome terrain roughness by allowing the clutch to slip, instead of dropping down a gear, which would be the correct procedure.
Adjusting the clutch is done as follows:
1. The cable is connected to A.
2. The clutch lever B is set, so that A has 5 mm room to move.
3. The cable is installed in place, i.e. C must be tightened so that A has no place to move around.
4. Test: The engine is set on idle, the hand brake is engaged, the clutch pedal is engaged, the both engines are set to 4th gear, the clutch pedal is slowly disengaged. Both clutches must operate in such manner that when the clutches are disengaged, both engines will stall. If not, the cable leading to the engine that did not stall or stalled too early must be followed, and the cable must be lengthened or shortened at "E".
Duplex chain/chain chamber
Transmission from the gearbox to the differential gear is via strong roller chains. The duplex chain is lubricated via an oil bath in the chain chamber. An inspection opening to allow checking of the chain oil level, is located on the front of the differential housing.
Too generous oiling will adversely affect the clutch operation so ensure that the proper oil level is maintained. Oil is poured into the filling hole until the level of the oil level screw on the side of the chain chamber is reached (drawing No 4b).
The recommended lubricant mixture for summer is a SAE 160 grade oil, while in winter a mixture of SAE 160 and SAE 40 at a ratio of 1:1 is recommended.
Tightening the chains requires a special clamping device. This job is best left to the VIDAL-Tempo service agent.
Changing the chains
The easiest way to change the chains is to remove the upper side cover of the chain covering and connect the old and the new chain together. When the old chain is pulled away, the new one will be pulled through. If the old chains are in any way damaged, the whole leftmost axle shaft and the chain covering must be taken off in order to reach to the differential.
Each of the differentials use of the chain wheel by means of a differential bolted to the cowl. Here are located the balancing wheels and small pulleys. Lubrication is carried out in conjunction with the chain using quality SAE 160 in the summer and a SAE 160 and SAE 40 1:1 blend during winter. The housing has lubrication nipples installed. (see drawing No. 5).
After 2000 km of driving the factory fitted carburetor can, if desired, can be replaced with a smaller main jet. Both carburetors are controlled by a common accelerator pedal (the right foot pedal). It is important that the air cleaner is cleaned every 500 km of driving because otherwise congestion in the cleaner can prevent the air flow and cause and fuel consumption to rise.
The fuel taps should be closed entirely (e.g. when the vehicle is left standing for more than a night) to prevent the fuel leakage.
Exhaust pipes and silencers are easily removed and must be thoroughly cleaned after every 5000 km of driving (2 to 3 months).
The chassis and frame, where it fixes to the bodywork, has set lubrication points which must be lubricated on a regular basis with thick SAE 160 gearbox oil. If the wagon is used regularly, this should be done at least every eighth day. Floor maintenance also includes all the nuts and bolts which are under continuous use and torsion, especially those that have moving parts.
All four axes of the drive shafts. The special drive shafts pass through the swivel support tubes. Each shaft has two joints, which should be lubricated with thick gearbox SAE 160 oil every 6 to 8 weeks. For lubrication the nipples must be removed.
If drive shaft disassembly is required, it is done by dismounting the differential, placing the shaft in a horizontal position and then pulling the entire shaft support tube out of the springs.
The springs are mounted to the differential casing with special brackets to the support tubes. A 17.5mm special key is required to detach the bolts (see drawing 5 above).
The foot brake (the middle pedal in front of the driver's seat) works on all four wheels. Braking is done by pressing the brake pedal (or by pulling the hand brake lever) which pulls the brake wires running to the brake hubs. Brake adjustment is done either by adjusting at the head of the brake cable or by adjusting the adjustment screw at the brake hub. The front brakes can be adjusted via adjustment screws at the hubs.
In each wheel hub are 2 roller bearings. The hubs are filled with a special installation of roller bearing grease which, depending on the use of the vehicle should last for many years.
Only skilled mechanics should carry out re-greasing of the bearings because the installation requires special care and expertise.
Steering is a via a worm control. Lubrication points are provided at the lower end of the clamshell housing. Use only quality SAE 160 lubricating grease. If the steering wheel is too loose, it can be adjusted by opening the clamshell housing, and adjusting the screws on the steering shaft that control the looseness of the eccentric sleeve. The steering shaft adjustment screw is located in the bottom of the clamshell housing. More signification steering gear repairs should be performed only by a VIDAL workshop.
Pressing the level next to the drivers seat forward engages rear wheel steering, allowing the rear wheels to move in conjunction with the front. This may be used for offroad driving where dramatic turns are required. Turning the front wheels to the right will turn the rear wheels to the left and vice versa. By pulling the control lever back, the rear wheels will be locked.
Note - Four wheel steering should be exercised only when running on four wheel drive or offroad.
On the instrument panel are the switches for each motor. To the right of the speedometer is the light switch. The positions are as follows:
1 = parking light
o = no light
2 = dim light (city light)
The headlamp is activated by a foot switch
To activate the lights you must engage the key-switch to the ignition circuit. Ignition is achieved by turning the key to the right. To turn off, turn it to the left. Remember to remove the key when leaving to the vehicle!
The red lights above the ignition switch monitor the circuit breakers. The left anterior light monitors the rear engine circuit. The right hand light, the front engine.
On the far right of the circuit-breaker is engine ignition. When setting the ignition is turned to the right it will start the rear engine, and when turned to the left will start the front engine.
When driving with only one engine the circuit breaker is regarded as an existing engine in the corresponding position. Otherwise, it is the position of the circuit-breaker shifts to be replaced, so that both engines would as much under load.(?)
The circuit breakers are located under the hood. They use 15 amp fuses. Ensure you always keep a few fuses handy in the event that a fuse blows.
Each motor has its own battery. Both are located under the front hood. Their charge is described above (see "Dashboard"). The batteries need regular care in order to ensure they are in good condition to start the motors. At least every four weeks the concentration and quantity of the acid must be examined. Also check that the cables are connected correctly and the battery terminals beneath the battery cover are greased with a suitable grease to prevent acid corrosion.
For more detailed maintenance, however it may be best to leave this task to a trained electrician.
The VIDAL- all-terrain wagon has two motors and is robustly and simply built and, correspondingly is easy to use when the following guidelines are followed:
- The vehicle can be driven using both engines at the same time or just one of the motors alone.
- When running both engines at the same time, the gear shift levers, located on the right hand side of the driver, need to be linked and used together.
- If running only the foremost engine, the rear engine gear shift lever must be decoupled and left in the free (neutral) position after detachment, the driver operating only the foremost gear lever. If running only the rear engine, proceed vice versa.
- When running the two engines, the engines should be run as closely as possible at the same speed. The rear engine may be run slightly faster than the front as the rear engine will encounter more resistance when pushing the vehicle’s weight.
- In any case, both the motor switches must be in the same position otherwise in difficult terrain or when driving on steep gradients, where one engine is not sufficient and the engine may stall, will subsequently stop the second engine.
- Each engine is started by its own electric starter motor and can be started independently.
When driving at a limited speed it is better to use only one motor. On long journeys, it is good to use the engines in turn to equalize wear. Before moving on to the difficult terrain, both engines should be run so that they are synchronised and equally warmed up.
Four-wheel steering is used only for off-road or turning in a small area. When driving on the street only use the front wheel steering (see "Control").
Front wheel steering on the streets or good terrain is not recommended, however, the driver must get used to the car’s behavior when driving with dual control, for example, when you turn to the left, the front end turns to the left and the rear end turns to the right. This fact must always be taken into account when driving in a cramped site.
The wagon’s two-stoke motors are powerful enough to overcome even large cross-country obstacles so there is no need to run at full throttle in difficult terrain or steep inclines. On the contrary, it is highly recommended that the inclines are taken at as little throttle as possible so that there is a reserve of power to overcome challenges. Also, the engines suffer increased wear at excessive speed.
However, when tackling steep gradients care must be taken care that the engine speed does not suddenly become too much, but timely shift down into low gear.
Handle with care and caution if towing a trailer off road.
If the car has not been used for a while, especially during the winter, the clutch plates may hold on to each other due to the stiffened oil. The easiest way to separate them is to set to the fourth gear, while the brakes are on, and let the engine pull them apart slowly and easy. This will usually separate the plates during the first try. Anyway, the clutch must be disengaged."
In particular, do not misuse or force any of the controls, switches or devices. Calm and considerate driving will deliver surprisingly good performance.