Linear Technology Actuator failed
The actuator no longer moves, runs roughly or fails intermittently. Often only one assembly is affected, not the whole drive.
Knowledge · Retrofit
Retrofit of old electric linear actuators: when the original drive is no longer available
An old, defective or discontinued electric linear actuator rarely means the end of the system. This page shows how to proceed – from the starting situation through the helpful information to the paths of repair, spare part, functionally equivalent replacement or improved new solution. You do not need to know all the data for this: a photo and the type plate are enough to get started.
In brief
Even when the original drive has failed, the manufacturer no longer exists or spare parts are discontinued: there is almost always a viable path to preserve the motion. You do not have to analyse the system yourself or know all the data – a photo and the type plate are enough to get started. S+R draws up an assessment and compares repair, spare part, functionally equivalent replacement and technically improved new solution to recommend the economically and technically suitable path.
Starting situation
Typical starting situations for a retrofit.
Most retrofit cases begin with one of these situations. In all of them the motion can be preserved – the only question is by which path.
Manufacturer no longer available
The original supplier no longer exists or no longer offers the series. The motion is still needed in the system regardless.
Type plate available, but no drawing
Only type and serial number are known. From the type plate, a photo and the installation situation, the assembly can usually be reconstructed.
The system has to keep running
A long standstill is not an option. What is needed is a solution with calculable risk and a dependable delivery date.
Spare part no longer available
Screw, motor, encoder or control are discontinued. Then it comes down to whether repair, rebuild or retrofit is the faster and safer path.
Inquiry
Which information helps – and why a little is already enough.
The more of it is available, the faster the evaluation. But no one has to answer the whole list: a photo and the type plate are already enough, S+R clarifies the rest in the callback.
Photo
An image of the installed actuator often shows design, mounting and condition better than any description. Even a phone photo is enough.
Type plate
Type, serial number and manufacturer are the quickest starting point – even when nothing else is available.
Installation dimensions
Rough lengths, mounting distances and connection position. A sketch or a photo with a tape measure is enough to begin with.
Stroke
The travel from retracted to extended – an approximate figure is enough.
Estimated load
What does the actuator move? Load weight or order of magnitude rather than an exact kN figure.
Control
How is it actuated: limit switches, potentiometer, encoder, 0–10 V / 4–20 mA, PLC? Even "I am not entirely sure" is a useful answer.
End positions
How are the end positions detected and held – mechanically, via switches or via the control system?
Environment
Indoors or outdoors, moisture, dust, temperature, chemicals. From this follow protection class and material.
Machine function
What the machine is meant to do often helps more than any single figure – the rest can be derived from it.
Decision
Five paths – from repair to a new solution.
Which path fits follows from the assessment. Often it is a combination – for instance a spare part today, a documented replacement strategy for tomorrow.
Repair / overhaul
When the assembly can be economically overhauled: replace wear parts, test and reinstall. The fastest path when the assessment supports it.
Spare part / original part
When only one component is defective and can be identified: replace screw, nut, bearings, motor, limit switch, encoder or control specifically.
Functionally equivalent replacement
When repair is no longer worthwhile: a mechanically and electrically matching actuator that fits the existing installation space and interface.
Technically improved new solution
When it is being replaced anyway: the same installation situation, but a better screw, sensors, protection class or control connection.
Series / OEM replacement strategy
When the system exists multiple times: a repeatable, documented replacement assembly instead of many one-off solutions.
Assessment
What S+R checks technically.
The recommendation emerges from these points. You do not have to answer them yourself – this is exactly the part that S+R takes on.
Mechanics & screw
Wear on screw, nut, guide and bearings – is an overhaul technically viable?
Motor & sensors
Motor, brake, limit switches and encoder: still identifiable, replaceable or worth modernising?
Interface & installation dimensions
Mounting, installation space, connection and stroke – does the replacement fit without modifying the machine?
Repairability
Are the required parts available or discontinued? Is the effort worthwhile compared with a replacement?
Cost-effectiveness
Repair, retrofit and new part compared – including risk and a realistic delivery date.
Documentation
What stays traceable: drawing, calculation and interface for the next service case.
In practice
Four examples from the installed base.
From the lock system after 20 years to the harsh production environment – the starting situation decides the path.
Lock system
A heavy-duty actuator comes back after roughly 20 years – assessment, spare-part assignment and service-life extension instead of a complete rebuild.
View reference →Existing machine
An old drive is no longer economical to repair. A mechanically compatible retrofit replaces it without modifying the machine.
View reference →Test bench
An older positioning axis is to remain reproducible and data-capable – a replacement with a defined, documented interface.
View reference →Harsh plant operation
Heat, dust and high forces challenge the assembly – a robust custom or replacement actuator for continuous operation.
View reference →FAQ
Common questions about retrofit.
I only have a type plate and a photo. Is that enough?
For a start, yes. From the type, serial number, a photo and the installation situation, the assembly can usually be reconstructed. S+R clarifies the missing details in the callback – you do not need to know everything in advance.
The manufacturer no longer exists. Can S+R still help?
Yes. S+R assesses the old unit as an assembly in its own right, checks the condition and interface, and develops a matching replacement – independently of the original supplier.
Is repair or replacement more worthwhile?
The assessment decides: wear, parts availability, cost-effectiveness and delivery date. S+R compares repair, spare part, retrofit and new part and recommends the most viable path.
Do I have to modify the machine?
Usually not. The aim is a mechanically and electrically matching replacement that adopts the existing installation dimensions, mounting and control – a modification is the exception, not the standard.
What happens after my inquiry?
S+R records the data, draws up an assessment and compares the paths. You receive an evaluation with next steps, risk and delivery date – and then decide at your own pace.
Send a photo or short description – callback for technical clarification.
An image of the installed actuator and the type plate are enough to get started. S+R draws up the assessment, compares the paths and gets back to you with an evaluation including next steps and delivery date.