On a side discharge spreader, the expeller and its hammers do all the throwing. If they’re worn, out of balance or the wrong shape, the spread pattern suffers. Here’s what manure spreader hammers do and what to look for. Start with the manure spreader guide if you’re new to the types.
How a side discharge expeller works
Augers in the hopper move manure toward a door at the side. Behind the door a fast spinning expeller with hammers hits the manure and throws it out. Door size, hammer shape, swing diameter and balance all change the pattern.
Hammer shape
A square tip keeps a flat impact face as it swings. A rounded tip loses efficiency as the angle changes. LEO uses a wider, square tip on the fabricated hammer across the whole 20 Series.
Hardfacing
Hammers wear on the front edge and the sides. LEO hardfaces the front edge and both side faces, which is where the abrasion happens.
Swing diameter and tip speed
A bigger swing diameter gives more tip velocity at the same RPM. The LEO expeller has a 22 inch swing diameter, with 15 hammers and 2.8 inches of expeller width per hammer.
Door size
The door controls how much material reaches the expeller. LEO 20 Series doors are 21 inches high and 42 inches wide (882 square inches). A large door helps with pen packed manure.
Balance and vibration
An unbalanced expeller shakes bearings and bushings apart. The LEO expeller is dynamically balanced, and every model uses the same 2.5 inch expeller shaft, which keeps parts simple.
Signs your hammers need attention
- The spread pattern gets shorter or patchy.
- More vibration than usual.
- Hay and straw wrapping the expeller.
- Hammers visibly rounded or thin.
Hammer kits
LEO hammer kits are available for other brands of side discharge spreaders too. Ask your dealer.
Rear discharge machines
On vertical beater spreaders the beater tips do the same job. See manure spreader beater tips.
Fewer hammers, same door area
More hammers isn’t always better. The LEO expeller uses 15 hammers on every model with a 22 inch swing diameter. That keeps rotating weight down, which helps balance and cuts vibration. An extra piece of reverse auger flighting in front of and behind the door builds pressure in the middle, pushing material out faster and more evenly.
Checking your expeller
With the tractor off and PTO locked out:
- Look at each hammer for rounding, thinning or cracks.
- Check that hammers swing freely.
- Spin the expeller by hand and feel for rough bearings.
- Look for wrapped straw or twine on the shaft.
- Check the splash guards and deflector shield.
When to replace hammers
- The tip is visibly rounded or thin.
- The spread pattern is shorter than it used to be.
- Vibration has increased.
Replace hammers as a set to keep the expeller balanced.
FAQ
### Why are hardfaced hammers better?
Hardfacing on the wear zones slows abrasion, so the hammer keeps its shape longer.
### How many hammers does a LEO expeller have?
15 hammers on every 20 Series model.
### Can I fit LEO hammers to another spreader?
LEO hammer kits are available as replacements for other side discharge spreaders. Ask your dealer.
How the expeller affects your spread pattern
The expeller throws manure in an arc to the side. Higher tip speed throws it further and breaks it up more. The 22 inch swing diameter on the LEO expeller gives more velocity at the point the hammer hits the material. A dynamically balanced expeller keeps that pattern steady from the first load to the last, because it isn’t shaking itself loose. When the pattern starts getting shorter or patchy, look at hammer wear before you blame the operator or the manure.
Door height and pen pack
The 21 inch door height and 42 inch door width on the 20 Series give an 882 square inch opening. Pen packed manure moves through a big opening without bridging, so the expeller gets a steady feed.
A final word
Think of the expeller like a set of fan blades. If one blade is worn more than the others, the whole thing shakes. That’s why hammers should be checked and replaced together, and why a dynamically balanced expeller matters. Vibration doesn’t just feel bad from the seat. It wears bushings and bearings, loosens bolts and slowly cracks welds. Keeping hammers even and the expeller balanced protects the whole machine.
Next step
See the LEO 20 Series side discharge manure spreaders or ask about hammer kits through a LEO dealer.
Learn more about LEO Agriculture and our full line of feed mixers and manure spreaders.
