A gearbox is down, the part is obsolete, and the original maker no longer supplies it? EKINSUN machines the replacement — gears, shafts, keys and housings — to your drawing or reverse-engineered from the worn part itself. No drawing or manufacturer reference needed. Quote in 24 hours.
A Replacement Gearbox Part — Even With No Drawing
Most people who search for a "custom gearbox manufacturer" don't need a brand-new gear train designed — they need one part remade so an otherwise-good machine runs again. That is exactly what we do. Send the failed component and, where possible, its mating part. We measure it, recover the geometry, and machine a correct replacement. For a gear we don't trace the worn teeth — we derive the gear from its numbers (tooth count, module, pressure angle), so even a chipped sample produces a part that meshes perfectly.
Gearbox Parts We Manufacture
| Part | What we make | Typical material |
|---|---|---|
| Spur & helical gears | Module ~0.5–8, any tooth count, bore & keyway to fit | 4140 / 8620 case-hardened steel |
| Bevel & worm gears | Worm and worm wheel sets, straight bevels | Steel worm + bronze wheel |
| Gear & output shafts | Splined, keyed, stepped — turned and ground | 4140 / 4340 steel |
| Pinions & cluster gears | High-ratio pinions, multi-gear blanks | Case-hardened alloy steel |
| Housings & covers | Milled housings, bearing bores, end covers | Aluminium or cast-iron equivalent |
| Keys, spacers, bushings | Drive keys, spacers, bronze bushings to size | Steel, bronze |
Honest scope: we manufacture the machined components of a gearbox and reverse-engineer discontinued ones. Bought-in items like bearings and seals are standard catalog parts — you source them, or we include them on request. We reproduce and upgrade existing gear trains; we don't design new ratios from scratch.
Reverse-Engineer an Obsolete Gearbox Part
This is the heart of the job. A gear's geometry is defined by a handful of standard parameters, so a worn or broken sample still yields a perfect new part — see how we derive a tooth form on our custom spur gear and custom worm gear pages. Shafts, keys and housings are measured directly. The full process is on our reverse engineering page, and the steel spur gear batch case shows it in practice. If your part is simply discontinued, our guide to replacing a discontinued gear walks through what we need.
Material & Hardening — Make It Last Longer
For power transmission we machine gears in 4140 or 8620 steel and harden them so the new part matches — or outlasts — the original. Surface hardening (case-hardening or nitriding) can raise allowable contact stress roughly 2–3× over a through-hardened gear, so a forced rebuild is a chance to upgrade a part that kept failing. Worm wheels are cut in bronze against a hardened steel worm; light-duty drives can use bronze or even Delrin. Tooth form, bore and shaft fits are verified on inspection.
Repair vs. Replace — Why a Remade Part Wins
When a single gear or shaft fails inside an otherwise sound gearbox, buying a whole new unit (if it even exists) is the expensive path. Remaking the failed component — often upgraded in material and hardness — gets the machine running for a fraction of the cost and keeps the rest of the proven assembly in service. For discontinued units it is frequently the only path.
Gearboxes We Supply Parts For
- Industrial reducers — worm and helical gear units on conveyors, mixers, pumps
- Machine-tool gearboxes — lathe and mill head/feed gears
- Automotive & motorsport — classic and discontinued transmission gears and shafts
- Marine, agricultural & material handling — drives where the OEM no longer supports the unit
Frequently Asked Questions
Yes — our most common gearbox job. Send the worn or broken part and its mate if possible. We recover the geometry — for a gear we derive tooth count, module and pressure angle — and machine a new part that fits. No drawing or manufacturer reference needed.
We manufacture the machined components — gears, shafts, keys, spacers and housings — and can reverse-engineer every machined part of a discontinued unit. Bearings and seals are catalog items you source or that we include on request. We reproduce and upgrade existing gear trains rather than designing new ratios.
Usually 4140/8620 steel (case-hardened), 4340 for high load, bronze for worm wheels and light-duty gears. We match the original or upgrade it — surface hardening can raise contact-stress capacity 2–3×.
Yes, MOQ 1 piece — a single gear or shaft to get a machine running, or a batch of spares. No minimum order.
Industrial reducers, machine-tool gearboxes, automotive and motorsport transmissions, marine, agricultural and material-handling drives. If a gear, shaft or housing can be turned, milled or hobbed, we can reproduce it.
Quote a Gearbox Part
Worn part, drawing or specs — all accepted. Reply in 24h.
// Qty & price
1 pc
Get it running
Single replacement part
3–10
Unit price drops
Spares on the shelf
10+
Best price
All tiers quoted upfront
- →No distributor — you pay the maker directly
- →CAD saved after first order — reorder spares anytime