27 March 1998

FANCY A SELF PROPELLED?

What should you poke and prod when going though a

second-hand self-propelled forager? Tips from Howard

Pullen and Terry Tremlett of Claas specialists Southern

Harvesters are passed on by Andrew Pearce

WHEN that old trailed forager wears out or no longer delivers enough output, its clearly time for a change. Switching to a contractor is an obvious and usually painless option taken by many, particularly where maize features.

But with those who must keep control over their own destiny, the notion of something large and self-propelled may flit through the mind.

Its quite a thought – a high-output machine, maybe shared with a neighbour or two, waiting to go at the turn of a key. Grass forage weather worries minimised, maize no problem.

There is the small snag of shifting all that output from field to clamp, then dealing with it on arrival. But assuming that end of things can be handled, all thats left is to find a good forager. These are big beasts, potentially able to consume money as fast as they gobble a swath, so its best not to get it wrong.

In reality there is little to fear, reckons Southern Harvesters sales chief Howard Pullen. "The internals of a self-propelled are pretty much the same as a trailed machine, and the powertrain is like a combines.

"Only the maize header, corn cracker and chute impeller are additions. The core of Claas foragers – the engine, transmission and frame – should be good for at least 10,000 hours, and all the crop-handling parts are replaceable."

Mr Pullen points out that the first 600-series models arrived here in 1983-4. Given that farmer-owners log around 500 hours/year or less and that contractors average 700 hours/year, even an old machine thats been looked after well – or overhauled properly – should have a lot of life left. And as Claas self-propelleds take a 7.7m (25ft) mower conversion, demand from contractors means theres always value in them.

Fine tooth comb ready?

Claas master mechanic and forager specialist Terry Tremlett guides us through the checks on a used machine, starting at the header and following crop flow.

"The front end is usually the most neglected area," he says, "So its worth spending a lot of time looking that over. Once the crop is into the cutting cylinder its generally OK."

The following pictures are taken around a 695 Mega SL, although the principles apply to any make.

THE FORAGER WORLD WAY

The Claas Group runs Forager World, a UK-wide dealer network specialising in (you guessed it) used foragers. At any time theres around 50 self-propelled units on offer, with prices starting at £15,000 for a checked and warranted machine. Warranty cover provides a £1500 fund, which can be drawn on for up to 12 months at any dealership to provide parts, service or labour .

1 Header condition is an accurate pointer to the rest of the machine, reckons Terry Tremlett; if its knocked about, look very critically elsewhere. Lifting fingers finds wear in bearings and cam tracks, wiggling them finds looseness.

2 Check auger bearing play by lifting sprocket with a bar. Does the auger turn backwards easily by hand? Scrapes and scroops from either end suggests wear has let the auger slump on to its shrouding. Look closely at auger flights and centre impellers – fatigue cracking will need work. Around the back of the header, a vertical chain takes drive to the auger slip clutch. If clutch nuts are wound down so tight that the springs are coil bound, either the clutch is worn out or oily. Either way, it needs to be fixed or shaft breakage is not far off.

3 With chain drives anywhere in the machine, assess wear by looking at the teeth – any hooking calls for new sprockets and chain. For a quick check on chain wear, try pulling it clear of the sprocket. If daylight appears the chain is past its sell-by date.

4. A familiar object seen from an unusual angle? If possible, stand a maize header up so the dividers point skywards. Looking underneath, the chain backing strips need to be in good order or gathers will move apart and not grip stalks properly. Cutting disc diameter must be enough to produce a good overlap. Play in disc shafts must be minimal or discs will open up in work.

4. A familiar object seen from an unusual angle? If possible, stand a maize header up so the dividers point skywards. Looking underneath, the chain backing strips need to be in good order or gathers will move apart and not grip stalks properly. Cutting disc diameter must be enough to produce a good overlap. Play in disc shafts must be minimal or discs will open up in work.

5 For the next bit the header needs to come off. All feed roller bearings must be checked – this top one pivots, so lifting it wont find play. Instead, Terry Tremlett levers it sideways. Worn plates on the roller housing are no problem – theyre replaceable.

6 The rest of the feed roller bearings can be checked with a bar. The kidney gearbox (arrow) and its bigger, highly-expensive, six-speed counterpart around the other side are often filled with grease. With these, the only option is to run the machine and listen closely for noise.

7 One of any self-propelleds big pluses is the metal detector. A high-tech broomstick and length of wire is vital to let you stand out of harms way when tempting it. Feed rollers must stop really smartly as the wire goes in – theres little safe passage length between rollers and cylinder. If not, the systems pawl assembly needs urgent attention. While youre at it, see that the feed roller reversing system works promptly.

8 Under a lid at the top of the feed roller unit is this sliding shaft. If it seizes, bends or wears, roller upward movement cant be accommodated and something has to give. The only way to see its OK is to unbolt it.

12 Turn to the corn cracker. Rollers need good ribs like these to work effectively – worn or damaged ones wont do much of a job and silage quality suffers. Lever between pulleys to find dodgy bearings.

9 Drop off the feed roller unit and look around the back. This scraper bar keeps the bottom plain roller clear. If its worn out or mis-set for height, feed problems follow.

13 The tower takes all the spout loadings. Acid can rot it on older machines; this new 800-series one is easy to find, but to check others youll have to crawl into the bowels. The impeller lives inside and is not easy to lay hands on – luckily not much goes wrong with it.

10 A more significant bar is needed to find play in the cylinder bearings. Then turn to the main drive belt). Pull it round, looking for damage or frayed cords – a new one is expensive.

11 For minimum-power clean chopping, the cylinder unit has to be in tip-top order. A reversible shearbar is easily turned, changed or adjusted. Blades should be free from nicks or bigger damage, both of which hit performance; replacements are not cheap. Spin the drum by hand, looking for signs of buckling in the webs and along the shearbar – very expensive to fix. Also find the sharpening stone and see how much life is left in it, and duck under to see whether the concave has any significant damage.

14 What IS this man doing? Checking for wear in the spout. Lining plates are replaceable.