Brewers' auto DAF
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SCOTTISH and Newcastle Breweries have taken delivery of a DAF 2300 tractive unit fitted with Allison fully automatic transmission.
The vehicle will be used to carry beer in barrels between the various S & N breweries located in the Edinburgh area.
Automatic transmission was specified as the routes between the breweries involve a great deal of urban work. With the kind permission of Scottish and Newcastle Breweries' transport department, I was able to try the vehicle in its home environment, writes Steve Gray.
Scottish and Newcastle are very keen on trying alternative transmissions and already have a DAF 2800 DKS fitted with the ZF Transmatic transmission which gives it effectively a semi-automatic box. This particular vehicle is used on trunking operations to Newcastle and so the extra power is needed.
However, during my trial of the outfit — carried out fullyladen in extremely snowy and icy conditions — the DAF proved to have very good acceleration. It was possible to get to a reasonable speed quite quickly — in my opinion faster than even an experienced driver could achieve with a manual box.
A definite technique is needed with the Allison though, as half throttle, if maintained, causes the box to shift up and down rapidly and at the same time gives a jerky ride.
I found that changes in the lower gears were a little jerky, even if full throttle was applied throughout.
The box used on the 2300 is the Allison MT 654 CR but in this application the TC 494-1.9 torque converter ratio is used. Five forward gears are provided and the box has a capability of up to 198kW (266bhp) maximum.
Input speed is restricted to 300rpm maximum and net input torque is 1060Nm (7801bft) which fits in nicely with the DAF's 169kW (230bhp) output at 2,400rpm and 775Nm (5721bft) maximum torque figures. Gear selection is by means of a neat lever to the driver's left. Shift sequence is shown in the diagram.
One particularly good feature of 654 box and its installation in the DAF is its link to the exhaust brake. Depressing the exhaust brake pedal progressively shifts the box down and slows the vehicle, but it is so designed that the vehicle cannot be stalled.
There was a certain amount of vibration when slowing and I asked the DAF engineer what caused it. He explained that there was a resonance between the torque converter and the vehicle's final drive. It was not excessive, however, and did not impair the performance or become obtrusive,