Underspecified gearbox
Spot quotes that mention only "standard gearbox" or ratio without torque, duty, service factor or datasheet.
For buyers comparing gearbox scope and maintenance teams investigating drive issues
EOT Crane Gearbox Guide
Compare gearbox ratio, service factor, mounting, lubrication, leakage, noise and spare support before treating two crane quotes as equivalent.
Quick answer
An EOT crane gearbox quote should state make, model, ratio, service factor, rated torque, duty basis, mounting, lubrication, seal/bearing details, datasheet, spare availability and substitution rules. Ratio alone is not enough because a cheaper gearbox may have lower torque margin, weaker duty, poor sealing or slow spare support.
Immediate value
What this guide helps you catch
Maintenance risk
Check leakage, noise, overheating, backlash, mounting, seals and lubricant access before accepting the crane.
Spare support gap
Make bearings, seals, oil, gear set, coupling and replacement lead time part of comparison.
Buyer specification schedule
Gearbox fields to compare in a crane quotation
| Field | What to ask | Why it matters | Red flag |
|---|---|---|---|
| Make and model | Gearbox manufacturer, model/series and datasheet. | Allows actual comparison and spare verification. | "Standard make" or no model. |
| Ratio | Reduction ratio and output speed basis. | Must match motor speed, wheel/drum speed and required crane motion. | Ratio stated without output speed. |
| Torque rating | Rated output torque, service factor and duty basis. | Shows whether gearbox is suitable for load, starts and shock. | No service factor or torque value. |
| Mounting and shaft | Foot/flange/shaft-mounted design, shaft size and coupling interface. | Affects alignment, maintenance and replacement compatibility. | Mounting unclear or nonstandard without drawings. |
| Lubrication | Oil grade, quantity, drain/fill access, breather and maintenance interval. | Poor lubrication access leads to neglected maintenance and early wear. | No lubrication information. |
| Seals and bearings | Seal type, bearing type, enclosure and expected spare availability. | Leakage and bearing failure are common downtime causes. | No spare part identification. |
| Inspection evidence | No-load run, noise/vibration check, leakage check and dispatch records. | Prevents accepting a problematic drive after installation. | No FAT or SAT gearbox check. |
Maintenance clues
Symptoms that should trigger gearbox inspection
Visible or measurable symptoms
- Oil leakage at shaft seal, cover joint or drain/fill plug.
- Oil contamination, metal particles or burnt smell.
- Abnormal noise, vibration, overheating or repeated trips.
- Loose mounting bolts, cracked base or coupling misalignment.
- Backlash, jerky travel or uneven bridge motion.
Root causes to check
- Incorrect gearbox duty or service factor.
- Poor alignment between motor, brake, coupling and gearbox.
- Incorrect oil grade, low oil level or blocked breather.
- Shock loading, skew, wheel binding or rail alignment issue.
- Seal wear from dust, heat, corrosion or shaft condition.
Copy-ready message
Vendor clarification wording
Send this when the quotation does not clearly identify gearbox rating and serviceability.
Engineering boundary: This guide supports procurement and maintenance checks. Final gearbox selection, torque verification, drive sizing, alignment and return-to-service decisions must be confirmed by qualified engineers, vendor documentation and site procedures.
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