Save Repair Costs—Automa illy
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R. D. CATER
NOW available for certain applications fitted with the Borg-Warner Type 35 automatic transmission, the BMC J4 in this form offers a new conception in city and house-to-house delivery and could overcome the everincreasing difficulty of obtaining good sales roundsmen who are also sympathetic vehicle handlers. When tested by The Commercial Motor (August 3. 1962). the Morris 14. fitted with the 1.5-litre diesel engine, proved to be more economical than its petrol-engined counterpart by up to 50 per cent. While testing this diesel van in Austin form recently, fitted with the automatic transmission, 1. found that it was almost impossible to misuse either the power unit or the gearbox. Admittedly, fuel consumption was greater by about 20 per cent compared with the same model fitted with a manual gearbox, but the makers claim that differences occurring with a number of drivers are considerably reduced; so, if a fleet averages 35 m.p.g. with manual gearboxes, it might well prove to be not very much
worse than this figure with automatics. Among other advantages claimed for this automatic version are that there is less wear and tear on the transmission in general, and that tyre life is increased. , The handling and riding qualities of the J4 remain unchanged, as do the dimensions and other details of specification. Two points seem to require attention, however. The first concerns the steering, which appeared to be rather on the heavy side when manoeuvring in close quarters. This could be because of the very high-geared steering (21 turns lock to lock) plus the fact that, with an evenly distributed load, the front wheels carry more weight than the rear.
The second point was that the floor of the cab on the driving side became saturated with slush and water after I had climbed in and out only a few times.• By lowering the sill, which stands proud of the floor by about 4 in., it would be possible to allow water to drain away from this point and avoid a potential mt:spot a=.well as making the in-and-out driver more comfortable.
Operating the gearbox is a simple matter. The selector lever, which is mounted on the steering column, has five positions—lock-up, drive, neutral, reverse and park. The drive is taken to the gearbox through the torque-converter, which is capable of transmitting power from the engine with extreme smoothness and of providing torque multiplication between the ratios of 2 to 1 and 1 to I on an infinitely variable basis.
For all normal road conditions it is necessary only to select drive on the hand lever, release the handbrake and depress the throttle pedal. Hydraulic pressure within the gearbox will automatically select first gear, which will be held on full throttle until the road speed reaches 11 to 14 m.p.h., when second gear will be selected. Direct drive is engaged when the road speed reaches 20 to 30 m.p.h. From this stage all the variable requirements will be absorbed by the torque-converter.
Kick-down device
Operating the throttle kick-down device (brought into action by pushing the pedal beyond the normal full-throttle position, and overcoming a spring) causes each ratio to be held for a longer period. Speeds obtainable in this condition are 19 to 22 m.p.h. in first gear and 33 to 36 m.p.h. in second. It is also possible, by using the kick-down position, to cause the gearbox to change to a lower ratio.
To hold a lower gear for the purpose of retaining control of the vehicle---for instance, when descending a steep hill --selecting the lock-up position causes the gearbox to select and retain second gear whilst the road speed is in excess of 5 m.p.h. Below this, first gear is automatically selected. Should bottom gear be required at speeds greater than 5 m.p.h. it is necessary only to depress the throttle pedal to kick-down position. Once this is done, however, the first gear will be held until the selector lever is moved back to the drive position. When the selector lever is returned to the drive position the gearbox reverts to fully automatic.
Park and neutral positions are the only two that will allow the starter to operate; neutral is self-explanatory, and park engages a pawl in the output shaft, so providing a second parking brake.
There is no doubt at all that, however bad a driver may be, he would find it very difficult to create conditions which would damage the Type 35 transmission. The progress of the test vehicle under all conditions was so gentle that it must be reflected in the down-time involved for fitting replacement parts. In fact, first impressions were that the vehicle was not performing very well: but my colleague, Tony Wilding, after testing the manual gearbox version of the J4 fitted with the diesel engine in 1962, commented: "To obtain adequate performance to keep up with traffic, the gearbox had to be used fully." Certainly this effort was eliminated with the automatic.
It is quite easy to be the first away from any traffic stop and to hold on to one's position in the traffic, even when in the company of private cars, without any undue effort on the part of the driver. After driving the van for about 300 miles I came to the conclusion that for the man whose first concern is not driving, this is the right machine. It is as simple to drive as an electric, and has none of the attendant disadvantages of restricted maximum speed and operating radius.
Several large companies are operating Austin or Morris J2 or J4 vans fitted with the Borg-Warner Type 35 transmission: one of these, British Bakeries Ltd., has more than 300 in its fleet and is reported to be obtaining very encouraging results. It has been said by British Bakeries that repairs to manual transmissions had been costing over £30 a vehicle each year, and that it was this which first tempted the company's transport management to try something different.
Not the least important factor in the choice of vehicles which may make something like 300 stops and starts a day is the effect that the driver's outlook will have on the serviceability of the machine. The roundman's first function is to sell: the fact that he may use a vehicle to do this is incidental.
Test figures
When looking at the test figures obtained from the automatic 14, it is evident that they are slightly lower than those obtained with the model having the manual gearbox. But one would not use a racehorse to pull a milk-cart. and the performance that is available is ample to cope with the type of operation for which the automatic version is intended. BMC offers the van in this form only for certain uses and states that it is unsuitable for operations involvinz full payloads and including very steep gradients. It is designed for the stop-start operations of the roundsman and the delivery driver, for which it is extremely able.
Carrying out the fuel consumption test over the Bartonin-the-Clay to Silsoe section of A6, it was noticeable, when completing the four-stops-to-the-mile, that the tedium of repeated gearchanging was lost in the complete ease with which one can simply stop and start again.
When carrying out acceleration tests I used the transmission in the drive position and, with the throttle in kick-down position, the results were, in my estimation, not bad. However, the impression was that they could have been improved. To discover whether this was so or not I repeated the tests, this time using the manual override, controlling the gear-changes. The results were so close that to annotate them would be quite irrelevant, and showed that although a driver might think he is making the best use of the gearbox, the automatic knows best. An advantage, of course, is that there is no loss of acceleration whilst the gears are actually being shifted, and it is here that the performance gain over the manual use of the change is obtained.
Hill-climb figures could, 1 think, have been bettered by using manual changes, but as it was snowing heavily by the time this part of the test was carried out, I did not try. The hill used was Bison near Dunstable which is 0-75 miles long and has an average gradient of 1 in 10.5, and a maximum gradient of 1 in 6-5. It took 3 min. 24 sec. to complete the climb, the minimum speed recorded being 10 m.p.h. while the lowest gear used was first. The automatic held this gear for I min. 35 sec. and at no time did the engine rev. excessively. Coolant temperature, checked at the start of the climb, was 72°C (161°F) and at the top of-the hill was 86°C. (188°F.). Ambient temperature was 3°C. (36°F.).
When the stop-and-start test on the hill was carried out, it was possible to move off easily in either drive or lock-up position. It was also a very simple proposition to move off without rolling backwards, and to hold the vehicle on a gradient by giving just a touch on the throttle. This, of course, is an exercise that can create severe damage to a manual clutch and gearbox assembly.
Turning the vehicle round and facing down the hill proved that there was just sufficient power to move off in reverse. Only after several atteMpts did I manage to get the van moving. Once it was mobile, however. it picked
up quite nicely. BMC state that tests carried out by them have proved it is possible to mote off from a standstill on a gradient of 1 in 4 with a full load, but they do not recommend that automatic transmission be used where grades as steep as this are encountered.. The handbrake held the vehicle easily, facing both up and down the hill. The braking figures obtained on the test were quite good indeed, as can be seen from the accompanying table and, in general, slightly better than those obtained in the 1962 road test of the J4.
Bad weather made it impossible to carry out fade tests by coasting down Bison Hill and these were made the next morning by driving for one mile at 20 m.p.h. against the brakes. The results were once again similar to those obtained in 1962, the Tapley meter reading being 66 per cent from 20m.p.h.—a drop of 30 per cent compared with the cold-drum tests.
As tested, the automatic J4 would cost £666, this figure being made up of £470 basic cost; £85 for the diesel engine; £80 for the automatic transmission; £13 for the heater and demister unit; £8 I 5s. for the passenger seat and £10 for painting.
For a vehicle that is as hard to misuse as this and which should, in my opinion, be good for about 100,000 miles of delivery service, this must be one of the most attractive propositions available to operators of this class of vehicle.