990 Series (1961-1968)

In October 1961, the David Brown Implematic range was improved and upgraded by the introduction of the 990 which, in the years that followed, would prove itself to be one of the best tractors ever to come from the Meltham factory. It was very similar to the 950, but it benefited from a bigger clutch, stronger back-end, heavier castings and a new type of engine with a cross-flow cylinder head.

David Brown 990

As Robin Kedward writes ‘What an engine this turned out to be! It retained the 3″ bore of the 950/880, but, with a much longer stroke of 4″ it developed 52.5 BHP at 2200 RPM. It was a power unit that would just laugh at rotaspreaders, wizzlers and forage harvesters. With that extra half inch of stroke this was, in my opinion, an engine with real “guts” – the harder you drove it the better it went. The 990 was sometimes criticised for its slow road speed (same as the 950), but I always thought this was more than made up for with the rest of the gears. No matter what you did with it, the 990 always had the perfect gear for the job.’ The matter of gearboxes is continued by Herbert Ashfield, who writes ‘The gear-boxes on this new range of tractors were just about as perfect as we could get them, and they were as reliable in service as anything we had made thus far and they really reflected the long tradition of David Brown’s gear-making. But the other thing I have to mention is the automatic gearbox, that came in on the 990.

Before that we’d done a torque amplifier, which was like a Laycock De-Normaville overdrive on a car, but we did it the other way around. Instead of giving an overdrive, it gave an underdrive. So in effect you got a 2-speed shift automatic, which split your gears; this gave a 12-speed gearbox and you also had a gear that went in-between each gear on the gearbox.

David Brown 990 Implematic

This meant that if you were ploughing and the tractor began to pant a bit, you could drop a gear without de-clutching or encountered a sticky patch this would pull you through. Now from that we developed even further, because I realised that if you put two torque amplifiers together, you could get a 4-speed automatic gearbox. We worked on this box, I should think about three or four years before we overcome all the problems because we were in uncharted territory. We required free-wheels and band-brakes and all sorts of odd things of which we had no production experience. Because of this we wanted to be really certain that we’d get all the bugs out, so we held back for quite a while; but when we release it, they put it into production straight away and it performed without any problems.

In the field they were so reliable, and very few problems were encountered, I know to this day that there are a lot of them working around here yet.’

David Brown 990 Tractor Selectamatic

The first model to leave the factory was number 440001, and, as with its counterparts, it could have been fitted with either five or six stud wheels as the six stud front wheels were not yet standard. Two six volt batteries were fitted under the seat, the same as previous models, but the air cleaner was now located in front of the radiator. All 990s had six stud rear wheels and were fitted with 11-32 tyres, although 13-28 were an option. This tractor sold like “hot cakes” from the word go and production was soon stepped up to meet demand, and as a result the 950 series was phased out in December 1962.

April 1963 soon arrived and along with it came number 453124, now fitted with height control. In August 1963 number 455561 saw the introduction of the fabricated front axle, which was a great improvement on the previous tractors which were fitted with the tall forged variety.

DB 990 Implematic

In August, more dramatic changes were to take place as a single 12 volt battery was now fitted in front of the radiator and the wheel-base lengthened by two inches. So, those who are thinking of restoring a later model 990, beware, the bonnet from an early 950 or 990 will not fit due to it being two inches shorter. A novel feature around this time was the fact that the new redundant battery boxes were fitted with different lids and became tool boxes. Two months later, in October, twelve speed transmission was offered as an option.

More minor changes took place in early 1964 and, commencing with tractor number 461120, the glass fuel bowl beneath the fuel tank was dispensed with in favour of a different type of lift-pump and a straightforward push-pull tap. Beginning with number 463764 David Browns began fitting a key-start on the right hand fuel tank support instead of the key and buttons on the left. However, more radical changes were on the way and, in May 1965, the 990 with the tool boxes beneath the seat disappeared and a new seat and seat support were introduced.

990

Also fitted were different mudguards, which were now bolted directly onto the rear axle and final drives. There was also a different drawbar, pick-up-hitch, three-way valve and the biggest change of all was the rear axle casing. The Selectamatic hydraulic system was obviously on its way and this latest type of axle casing was made in such a way as to facilitate  drilling the required holes for this system. However, until such times the holes were blanked, but it was obvious that the castings were being made in readiness for the change and the later Implematic castings even had a blanking plate for the dump valve! Were any of these ever fitted retrospectively with the Selectamatic hydraulic system one wonders?

The Selectamatic was to be a great success, and one which would continue through the years ahead, however by early 1965 things were beginning to change, not least the desire to introduce a new body shape and colour scheme. In October 1965 the last 990 Implematic (no. 480600) rolled down the line. In just over four years 40,600 990’s were produced, including some non-Livedrive and industrial models with twin plate clutches. It was a remarkable record which, at one stage accounted for 50% of the current production at Meltham Mills. The 1964 price list shows the 990 Implematic Livedrive with multi-speed pro. and live dual purpose extra lift hydraulics at the modest sum of £784.9s.0d (£784.45p), and the twelve-speed model at £815.14s.0d (£815.70p).

Some of the accessories were priced as follows: Foot throttle U 377 £2.12s.6d (£2.625p); 3-way hydraulic valve U 279 £10.0s.0d; pick-up-hitch U 385 £12.15s.0d (£12.75p) and a quite expensively £54.15s.0d (£54.75p) for power steering. Many farmers came to David Brown for the first time with the 990, and with the company they stayed until Case ended production at Meltham Mills. It was a tractor which bred real customer loyalty, but this loyalty was not easily won and it was satisfaction with the 990 that really put this model head and shoulders above its competitors.

VAK 1

(1939-1945)

VTK1 / VIG1

(1941-1949)

VAK 1A

(1945-1947)

VAK1C

(1947-1954)

Tracklayers

(1942-1963)

Taskmaster

(1948-1965)

VAD6 50D

(1953-1959)

900 Series

(1955-1957)

VAD12 2D

(1956-1961)

950 Series

(1958-1961)

850 Series

(1961-1965)

880 Series

(1961-1965)

990 Series

(1961-1968)