What to Send a Gear Manufacturer When You Need a Reverse-Engineered Replacement

When the manufacturer of a gear no longer exists, no longer supports the part, or simply never gave you a drawing, reverse engineering is usually the fastest way back to production. But the quality of the replacement depends almost entirely on the quality of what you send us. A gear reverse engineering specialist in Ontario can't measure a part they don't have, and they can't guess at tolerances that were never written down. This guide covers exactly what to gather before you request a quote.

1. Send the physical part, even if it's worn or broken

A damaged gear is still more useful than a written description. Tooth profile, pitch, and bore geometry can often be reconstructed even from a part with chipped teeth or wear, because the undamaged sections still carry the original geometry. If the part is in multiple pieces, send all of them - a broken tooth fragment can confirm module and pressure angle even if the rest of the gear is unusable for direct measurement.

If the machine can't be down long enough to ship the part, ask whether a loaner or rush return turnaround is possible. Most reverse engineering shops, including ours, understand that the part you're sending is often the only thing standing between your equipment and a production line.

2. If you can't ship it, measure it and photograph it properly

When shipping isn't an option, we can often start from detailed measurements and photos. At a minimum, capture:

• Outer diameter and bore diameter, measured with calipers, not a tape measure
• Number of teeth - count them directly, don't estimate
• Face width (the thickness of the gear along the shaft axis)
• Bore features - keyway width and depth, spline count, or set screw location
• Any stamped part numbers or manufacturer markings, even partial ones

For photos, use a plain background, shoot straight-on rather than at an angle, and include a ruler or a coin in the frame for scale. A close-up of the tooth profile from the side is one of the most useful single photos you can send - it lets us estimate pressure angle before the part ever arrives.

3. Tell us about the application, not just the part

Two gears can look identical and require completely different materials. Let us know:

• What the gear drives, and roughly how much load or torque it sees
• Operating environment - is it exposed to moisture, chemicals, extreme temperature, or heavy dust?
• Whether the original part failed from normal wear, overload, or a lubrication issue (this affects our material recommendation)
• How many units you need now, and whether you want spares made at the same time

This context is often what separates an exact copy from an improved replacement. If a gear keeps failing prematurely, matching the original material exactly may just reproduce the same failure - a harder alloy or a corrosion-resistant finish might be the better fix.

4. What happens after you send everything

Once we have the part, measurements, or photos, our process is typically:

1. CMM inspection to capture exact tooth profile, module, pressure angle, and bore geometry
2. Quote and material recommendation, usually within a few business days
3. First-article approval on larger orders, so you can confirm fit before full production
4. Manufacturing, with standard lead times of 2-4 weeks depending on complexity and quantity

If your part is urgent, say so up front - rush timelines are often possible, especially for single replacement gears rather than full production runs.

Ready to get a quote?

As a reverse engineering gear specialist serving Ontario and shipping across Canada, we've rebuilt gears for machinery where the original manufacturer has been out of business for decades. Send us what you have, and we'll tell you exactly what else we need.