A replacement spiral bevel gear project is an identification problem before it is a manufacturing problem. Wear, broken teeth, loose bearings and field modifications can change the part you see on the bench. The goal is to reconstruct the intended pair and mounting relationship rather than copy every damaged feature.
Record the complete assembly before dismantling
Photograph both members in position, mark the driving and driven components, record rotation if it matters, and measure the housing or bearing references that establish the gear position. If backlash can be measured reliably, record the method and assembly state.
These notes often become more valuable after the worn parts are removed, because the original relationship is otherwise difficult to reconstruct.
Identification checklist
| Evidence | What it can help establish | Caution |
|---|---|---|
| Mating gear | Ratio/tooth counts, hand and pair relationship | Inspect its wear and confirm it actually belongs to the same assembly. |
| Legacy drawing | Original geometry, interfaces and acceptance notes | Check revision and whether field modifications occurred. |
| Part number | Identification and historical reference | Do not assume a number alone proves the current geometry. |
| Worn sample | Interface dimensions, tooth count, general geometry | Wear/damage can hide the original tooth or mounting condition. |
| Housing measurements | Mounting position and shaft relationship | Use defined datums and note damaged bearings or looseness. |
| Photos before removal | Orientation and assembly sequence | Include a scale/reference and label viewing direction. |
Separate damage evidence from design geometry
Chipped tooth tips, pitting, polished contact areas and enlarged bores describe how the old part has lived. They can help a failure review, but they should not automatically become dimensions in the replacement drawing. Use undamaged areas, the mate and assembly data to establish the new controlled definition.
When only one member can be replaced
If the mating gear must remain in service, provide as much reliable data as possible: tooth count, hand, original drawing or scan, mounting position, visible condition and any quality information. Exact compatibility should not be promised until that relationship has been reviewed. In some cases the safer project may be a new matched pair rather than one replacement member.
Packing a physical sample
Protect teeth and datum surfaces from further damage. Identify which marks are existing service damage and which were added for orientation. Include a simple packing note that links each sample to the drawing/reference used in the RFQ so multiple parts are not mixed during review.
Before shipping a sample for review
Clean only enough to expose useful surfaces and markings; do not grind or polish away wear evidence. Protect the teeth, bearing seats and datum faces during packing. If two members belong together, tag them as one pair and include an orientation note. If several similar gears are shipped, assign each sample a unique reference that matches the RFQ and photos.
Include a short “known / unknown” sheet. It should state which values come from a drawing, which were measured from the worn sample, and which still need review. This prevents a bench measurement from being mistaken for an original design value.
Questions buyers often ask
Can one worn gear be enough to make a replacement?
Sometimes there is enough reliable information, but it should not be assumed. The mate, housing measurements or legacy data can be essential for reconstructing the original pair.
Should I replace both members?
That depends on the condition and how well the remaining mate is defined. A new matched pair may reduce uncertainty when the existing mate is badly worn or undocumented.
Can a part number identify the gear exactly?
It is useful evidence, but revisions and field changes can exist. Combine the reference with current measurements and the mating relationship.
Send the gear pair, drawing and duty in one RFQ.
The more clearly the mating relationship and assembly datums are defined, the faster the configuration can be reviewed.
Ordering & delivery guidance
MOQ is flexible by product type, manufacturing route and total order value. Suitable new projects may request 1–5 sample pieces at sample pricing. Mixed models can be combined when the order total reaches approximately USD 1,500. Orders of 1–2 pieces can be reviewed, although unit cost is normally higher.
Typical planning windows are 10–25 working days for standard parts, 20–45 working days for customized components and 45–120 working days for project-type equipment or assemblies. EXW, FOB, CIF and DAP are commonly supported; FCA, CFR, CPT, CIP and DDP can be discussed for the shipment.
