Most operators check the obvious things before a mixing season: knife condition, gearbox oil, scale calibration. The auger kicker gets a glance, maybe a tap with a boot, and that’s usually the end of it. Same size it’s always been. Probably fine.
It’s rarely fine. And the cost of running the wrong kicker, or a worn-out one, shows up in ways that are easy to misread — a batch that needs an extra five minutes, a tub that never quite cleans out, a ration that looks acceptable but hides dead pockets of unblended forage. None of those problems announce themselves loudly. They just quietly raise your per-batch fuel bill and chip away at herd uniformity.
What the Kicker Is Actually Doing
The auger kicker, sometimes called a kicker plate, leading edge plate, lead-edge scraper, or plow wing depending on who built your machine, sits at the outer lower leading edge of the vertical auger. Its job is to create what mixing technicians call a rolling boil: material scrapes off the tub wall, gets lifted up through the centre of the auger, cascades outward, and falls back down along the wall to be swept again. That continuous loop is how a vertical mixer achieves homogeneity. Without it, you get convection instead of circulation, and convection leaves zones.
Those zones are the dead spots operators notice but can’t always explain. Feed packs along the tub floor or stagnates against the wall. The auger is spinning, everything looks like it’s moving, but a portion of that material is just riding along rather than being actively turned. Extend the mix time to compensate and you risk over-processing; pull it out early and the ration is inconsistent. Either way, you’ve lost the batch.
The kicker prevents that by pulling material back into the auger’s cutting zone continuously. No accumulation on the floor. No stagnation at the wall. The torque demand drops because the auger isn’t grinding through packed material — it’s working through a constantly refreshed flow. Less resistance means less fuel burned per batch.
Auger Kicker Size and Why One Setting Doesn’t Cover Every Ration
Here’s where most operations leave money on the table. Kicker aggressiveness needs to match the ration you’re mixing, not just the machine you’re running. A dry high-hay ration behaves completely differently inside the tub than a wet silage-heavy mix, and the same kicker geometry that works well for one can create problems with the other.
High-forage rations need a larger, more aggressive kicker. Dry long-stem hay has a tendency to bridge and pack, so you need something that bites into the wall material with enough force to keep it moving. Back the aggressiveness off too much and you’ll watch your mix time creep up regardless of knife condition or ration sequencing.
Wet rations are different. A silage-forward mix is already dense and sticky. Too aggressive a kicker in that environment increases torque demand unnecessarily, and on higher-moisture loads you may actually see material compress against the wall rather than release cleanly. A smaller kicker profile suits wet rations better because it generates enough circulation without overpowering the flow.
LEO Agriculture‘s bolt-on kicker system addresses this directly with four discrete sizes: Small, Medium, Large, and an Extreme variant that adds a lip specifically for low-density material. The bolt-on design matters practically. Swapping kicker size to match a seasonal ration change, or replacing a worn plate, doesn’t require a fabricator — it’s a routine maintenance task. That’s the difference between a feature that gets used and one that sits as a theoretical option.
On V-design machines, there’s also the option to run without kickers for low-horsepower applications, which tells you something about how much the kicker changes the load on the drivetrain. It’s not a passive component.
For operators running smaller herds who may not think about kicker sizing as a primary variable, the same principle applies regardless of machine capacity. A compact vertical mixer produces inconsistent TMR for the same reasons a large one does when the kicker is sized wrong for the ration.
What Happens When the Kicker Wears Out
A worn kicker doesn’t fail dramatically. It degrades gradually, which makes it harder to catch. The first sign is usually mix time: batches that used to finish in a set number of minutes start needing more. Then you notice residue building up in the tub between batches, which slows clean-out and potentially carries over into the next load. Over time, torque demand rises as the auger works harder to compensate for reduced wall movement.
Dead spots return. You may see them at the corners of the tub floor, or along the lower wall on the trailing side of the auger. The ration looks mixed. Pull a sample from different points in the load and the particle size distribution tells a different story.
Higher torque means higher fuel consumption per batch. On a commercial operation running multiple batches daily, that adds up quickly. Wear on other drivetrain components also increases when the auger is working against packed material rather than flowing feed. The kicker is a wear item, but neglecting it creates wear across the whole system.
There’s a broader point here about how mix quality degrades in steps that feel minor individually. The kicker is one piece of it. Knife wear, auger geometry, and ration sequencing all interact. For operators thinking through where losses are hiding in their mixing process, it’s worth reading about how auger cutting geometry affects processing speed and fuel use, because the kicker and the cutting system work together rather than independently.
Matching Kicker to Ration in Practice
The practical rule is straightforward. More dry long-stem forage in the ration, go larger on the kicker. More wet silage or high-moisture byproducts, go smaller. The Extreme size with the lip is specifically for low-density material that tends to float or bridge rather than circulate, situations you’ll encounter with certain commodities or when running very light loads relative to tub capacity.
It’s also worth building kicker inspection into your regular maintenance schedule rather than treating it as an annual check. On high-throughput operations, kicker wear can progress faster than expected, particularly if you’re running abrasive rations or processing a high proportion of dry hay. A worn kicker that still looks structurally intact may have lost enough material from the leading edge to drop its effectiveness significantly.
Check the leading edge profile against a new plate. If the geometry has changed, the kicker has changed too — even if it hasn’t cracked or broken.
The connection between what happens inside the tub and what ends up in the feed bunk is more direct than it sometimes appears. Poor mixing creates segregation potential before the load even leaves the machine, and that gets worse in transit. If your delivery process adds further variation, the compounding effect on bunk uniformity is significant. That subject is covered in more detail here.
Running the right auger kicker size for your current ration is one of the lower-cost adjustments available to a TMR operation. The component cost is modest, the swap is straightforward with a bolt-on system, and the effect on mix time, fuel use, and ration consistency is measurable. Most of the operators who do it once don’t go back to running a single size year-round.
