---
title: "Toggle lubrication system of an injection molding machine"
url: "https://www.imspares.com/injection-molding-machine-parts/toggle/toggle-lubrication/"
---

# Toggle lubrication system of an injection molding machine

How the centralized lubrication of an injection molding machine toggle works: pump, distributors, oil or grease, signs of failure, checks and interval settings.

Injection molding machine lubrication on a toggle machine is done by a **centralized lubrication** system. A pump with its own reservoir sends small, metered amounts of lubrication oil or grease through distributors and tubing to every toggle pin and bushing, to the crosshead, and on many machines to the tie bar bushings and the moving platen slides. The controller starts the pump at a set interval, counted in mold cycles or in time, and raises an alarm when the level or the pressure is too low. A toggle with working lubrication wears slowly; one that runs dry wears out its bushings and pins quickly.

## Why the toggle needs a steady supply

The toggle joints swing through a limited angle under very high load, with the highest load at lock-up. Under that kind of motion a lubricant film does not build up by itself the way it does in a fast-turning bearing. The [pins](https://www.imspares.com/injection-molding-machine-parts/toggle/toggle-pins/) and [bushings](https://www.imspares.com/injection-molding-machine-parts/toggle/toggle-bushings/) rely on fresh lubricant delivered regularly to the surfaces, which also carries away wear particles and dirt. That is why the toggle is lubricated a little at a time, all the time, and not just once at a service.

## Parts of a centralized lubrication system

- **Pump and reservoir.** An electric pump with a reservoir, often with a level switch that warns before it runs empty.
- **Filter.** At the reservoir or the pump outlet, it keeps dirt out of the metering units.
- **Pressure switch or sensor.** It confirms that the system built pressure during each lubrication cycle.
- **Distributors.** Metering units or divider valves that split the flow into a measured amount for each point.
- **Tubing and fittings.** Lines from the distributors to each joint, with flexible sections where they follow the moving links.
- **Controller settings.** The interval, the pump run time or pressure, the alarms, and a key or button for a manual lubrication cycle.

## Types of distribution

The machine manual's lubrication diagram shows which type your machine uses.

| | Resistance (restrictor) type | Positive displacement injectors | Progressive divider |
|---|---|---|---|
| How it meters | Orifices sized for each point share out the oil | Each injector delivers a fixed volume per lubrication cycle | Pistons in the block feed each outlet in turn |
| Lubricant | Oil | Oil or soft grease | Oil or grease |
| A blocked point | Goes unnoticed; the others keep receiving oil | That point gets nothing; the others are still served | The whole block stops, so a cycle or pressure monitor detects it |

## Oil or grease?

The machine's design decides. Use only the lubricant grade in the manual: an oil or grease that is too thick may not pass through the metering units and reach the far points, and one that is too thin may not hold a film under the toggle's load. Mixing greases of different types can make them harden or separate and block the lines, so clean the system out if you have to change product.

The toggle's lubrication oil is usually a separate product from the hydraulic oil, in its own reservoir. Do not top it up with hydraulic oil unless the manual allows it. For the hydraulic system's own oil, see the [hydraulic oil guide](https://www.imspares.com/injection-molding-machine-parts/hydraulics/hydraulic-oil/).

## Signs that the lubrication is failing

- A low-level or lubrication pressure alarm on the controller.
- Joints that look dry, or lubricant at a joint that is dark, gritty or full of bronze-colored particles.
- Squealing or knocking from the toggle.
- One joint wearing faster than the others, often because its line is blocked or broken.
- A puddle of lubricant under one point: a broken tube or a loose fitting, which also means the other points get less.
- The pump runs but the pressure does not build: an empty reservoir, air in the lines, a worn pump or a large leak.

## Checking the lubrication system

1. Check the reservoir level and refill it with the specified lubricant before it runs low. Keep the filler and the container clean: dirt in the reservoir goes straight to the bushings.
2. Look for lubrication alarms on the controller, and find the cause before resetting one.
3. Start a manual lubrication cycle and check that the pressure builds on the gauge or the display.
4. Follow the tubing to every point. Look for crushed, cracked or disconnected tubes and leaking fittings, especially where the tubes flex with the moving links.
5. Check that fresh lubricant appears at each joint. To test a doubtful point, disconnect its tube at the joint and run a manual cycle: lubricant should come out.
6. Clean or replace the filter at the interval in the manual.
7. After any work on the toggle, run several manual lubrication cycles before moving the clamp, so the new pins and bushings start lubricated.

## Setting the lubrication interval

Start from the settings in the machine manual. If the joints look dry between lubrication cycles, the interval is too long or a metering unit is too small. If lubricant drips from the toggle onto the base, the platens or the mold area, the interval is too short or too much is delivered. Too much lubricant is wasteful and can contaminate parts and molds, which matters for medical and food packaging parts. Because the interval is often counted in cycles, a fast cycle automatically lubricates more often per hour than a slow one.

The tie bars and their bushings are lubricated by the same system on some machines and by hand on others: see the [tie bar bushings](https://www.imspares.com/injection-molding-machine-parts/tie-bars/tie-bar-bushings/) page and our [tie bar maintenance guide](https://www.imspares.com/blog/tie-bar-maintenance-replacement-guide/).

## What to send for a quote on lubrication parts

- The machine brand, model and serial number.
- Photos of the pump's nameplate (model, voltage and output), the reservoir, and the distributor blocks with their markings.
- The number of outlets, the tube outside diameter and the type of fittings.
- The lubricant the machine uses.

For the parts that the lubrication protects, see the [toggle mechanism guide](https://www.imspares.com/injection-molding-machine-parts/toggle/) and our article [Understanding your machine's toggle clamping system](https://www.imspares.com/blog/toggle-clamping-system-explained/).

## Questions

### What lubricant does an injection molding machine toggle use?

The one in the machine manual. Depending on the design, the centralized system runs on a lubrication oil or on a grease that flows through the lines. It is usually a separate product with its own reservoir, not the hydraulic oil.

### How often should the toggle be lubricated?

The interval is set in the machine controller, usually as a number of cycles or a time, and the manual gives the starting values. There is no universal figure: adjust it if the joints look dry between lubrication cycles or if lubricant drips from the toggle.

### What happens if the lubrication system fails?

The toggle pins and bushings run dry and wear much faster, the clamp starts to squeal or knock, and in the worst case a pin seizes or scores its bushing badly. Never keep running with a lubrication alarm.

### Can I use hydraulic oil to fill the toggle lubrication tank?

Only if the machine manual says so. The pump and metering units are designed for a lubricant of a certain grade, and the wrong one may not reach the joints or may not hold a film under the toggle's load.