Clutch is smooth operator

9 March 2001

Clutch is smooth operator

JCB announced a number of design improvements to its

Fastrac range, not least the Smoothshift clutch system,

at last years Smithfield Show. Andy Moore saw how

these upgrades performed in the field

Jack of all trades? JCBs Fastrac range offers smoother clutch operation, a shuttle push button and higher capacity hydraulic pumps.

New vertical wheel fenders are designed to protect the cab steps and door against mud and grime.

Gently does it… The Smoothshift oil-immersed clutch is much easier to operate than the previous knee-wrenching dry disc version.

PRODUCERS in the market for a new JCB Fastrac should not be disappointed when test-driving models fitted with the companys latest Smoothshift clutch.

Described by JCB as "bomb-proof", the clutch allows smoother take-up and transmission of draught loads when compared with earlier systems. This, says JCB, will allow the clutch to last over 6000 hours – the life of a Fastrac.

The Smoothshift clutch replaces the dry single disc version and comprises an oil-immersed 25cm (10in) diameter pack, which has 20% more surface area than the old version.

farmers weekly took advantage of an unusually dry day last month to take a 3185 coupled to a six-furrow plough out for the day.

Operators familiar with JCBs traditional knee-wrenching clutch pedal should be pleasantly surprised when working with the new, effortless version.

The new clutch system is operated by a series of potentiometers and switches which "talk" to an electronic transmission controller that, in turn, monitors engine speeds in relation to loads and activates an electro-hydraulic flow valve to control the clutch pack.

In practice, the Smoothshift clutch makes a significant difference to the overall performance of the tractor. Releasing the clutch gradually allows the tractor to achieve a smooth, jolt-free start. And there is an almost identical experience when starting under heavy load – in this case the plough.

Dip the clutch and the tractor – with its heavy plough – comes to an abrupt halt. Releasing it causes a small delay before the transmission controller allows drive to be reunited.

There is also good news for those who retain the questionable habit of riding the clutch. No longer is there the risk of taking precious millimetres of wear off the plates, or the clutch cooking itself into oblivion. And easier clutch control when inching up to implements for coupling should also be a welcome boon.

Turning the tractor and plough at headlands offered the chance to become acquainted with a new shuttle push button which performs the same duty as the clutch when selecting forward and reverse directions.

The shuttle operates the same pre-select system, but there is no need to depress the clutch when changing directions. Pre-selection is confirmed by pressing the button which sounds a buzzer, prompting the operator to move the lever in the desired direction of travel. Pressing the button again activates forward or reverse directions which are confirmed by a second sound of the buzzer.

The only grumble with the system is that the operator cannot simply flick the shuttle in the required direction and expect the tractor to follow suit. The lever is not a full powershuttle so the button must be pressed at the required moments. And the operator has to remember there is no detent neutral position on the shuttle.

If the shuttle lever is moved without pressing the button, the transmission automatically defaults to neutral which is displayed on the LCD dashboard.

To get out of neutral, the operator has to manually dip the clutch before operating the shuttle button.

Other updates for the Fastrac range include use of higher capacity hydraulic pumps. The 2115, 2125 and 2135 models have pumps rated at 103 litres/min, the 2150 99 litres/min, and the 3155 and 3185 tractors are fitted with 108 litres/min pumps.

In addition, all machines are now fitted with load sensing hydraulic valves designed to reduce power loss and provide the operator better control over implement settings.

Further refinements include "Zero Leak spool valves with float position, rate of drop control for front linkage and a hydraulic flow divider, plus vertical wheel fenders which protect the cab steps and bodywork from being caked in mud.

Overall impression? Although the Fastrac still lacks the advantage of a full powershift transmission, Smoothshift and the numerous improvements to the hydraulic system should help to steer its image towards an all-round machine capable of performing on and off-road duties. &#42


Engine 170hp Cummins.

Transmission 54Fx18R Synchro.

Hydraulics 108 litre/min load sense.

Lift capacity 7000kg.

Fuel capacity 350 litres.

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