When it comes to high hour horsepower, the fleet of Devon contractor Michael Tucker is impressive. His line-up of six John Deeres has clocked up more than 100,000 hours between them. Nick Fone takes a look at the hardest worked Ð a 39,800-hour 6400

In 2002 I was looking to change our 13,000-hour, J-reg JD 2850 and this 6400 was up for sale. It was one of a pair from a dairy farm where it had been the main tractor doing all the ploughing, muckspreading and other fieldwork.

• What made you buy it?

It was incredibly tidy and I really like the look of what was then the “new” John Deere 6000 range. The four-speed powershift and overall layout of the tractor really appealed to me.

 • What are its main jobs?

Although it’s done over 35,000 hours, it’s still one of our main workhorses. It’s doing an average of nine hours a day. This time of year it’s running the splash-plate on our umbilical setup but later on it will be on our six-row Accord maize drill.

As soon as we get into grass silage it will be towing one of our 13t Richard Westerns and then it will go on the baler/wrapper and usually pumps out about 11,500 bales a year.

It also does the corn-drilling with a 3m power-harrow combination and front-press. Other times it will pull an 11t Bunning spreader or the 2,400gallon Major tanker.

It used to do all the buck-raking with its Sumo front-linkage but now we’ve got the heavier 7810, we use that.

• What’s it like on fuel?

We did a comparison last year with our neighbour’s 6430 on the slurry pump. While the 6400 was using about 20-litres/hour, the new tractor was burning 29 litres/hour and it couldn’t pump nearly as fast.

• Is it well looked after?

As our oldest tractor it needs to be handled carefully so I spend 95% of the time on it. It needs an attentive ear to make sure it’s running as it should. It’s driven hard but carefully.

It gets an engine oil change every 250 hours and the back-end gets drained every 1,000 hours. We’re religious about it and only use genuine John Deere oils.

• Reliable?

Given its hours, it’s amazing.

Up until 13,600 hours we didn’t put a spanner on it. As you’d expect, by that point it needed a new head gasket and a change of clutch plates. We also gave it new injectors and replaced the fuel pump, which bumped up the power from 100hp to over 120hp. That cost about £3,000.

At 16,100 hours it had a new turbo and ran right through to 28,660 hours without a glitch. But then I noticed it had a weeping core-plug so we sent it in to the dealer. Once it was fixed they were running it up on the dyno and it threw a con-rod out through the sump.

At a cost of £3,500, a brand new engine was fitted with the old fuel pump.

Since then it hasn’t put a foot wrong.

Why run such a high-houred tractor?

It’s given so little trouble and it pulls so well – the power is unreal. It regularly overtakes the 6910 on the haul.

The big bonus is that we can fix nearly everything ourselves, but more importantly it costs less that £2.50 an hour to run it and service it, compared with over £7 an hour for our new 6930.

Will you hang on to it?

I won’t ever sell it. The aim was to get it to 30,000 hours and then park it up in the shed but the new engine has given it a new lease of life – it would be a waste to leave it sitting idle.

That said, the beauty of these John Deeres is that you can clock up tens of thousands of hours and they’re still worth something.