When noise, heat, or metal in the oil appears, the first question is not “which brand?” but “is the housing still an asset?” Anand Gears both repairs and replaces industrial reducers. This guide helps maintenance and production teams pick a path without inventing prices — your quote depends on what the inspector finds.
When repair usually makes sense
- Worn worm set only — housing bores true, no cracks, mounting faces flat. Fit a matched worm + wheel set, new bearings, and seals.
- Bearings and seals — mesh still good on contact check; noise is bearing-related. Reseal, re-grease/oil, and replace bearings to correct clearances.
- One damaged shaft — bent output end or chewed keyway while the gear teeth and housing are sound. Remake the shaft to the millimetre print of the original.
- PB wheel wear with good centre — re-rim or new solid wheel as part of a matched set if the hub geometry is worth keeping.
Repair keeps foundations, couplings, and guards untouched. Downtime is often dominated by strip-and-inspect, not by waiting for a full new casting.
When full replacement is the better call
- Cracked or porous housing — oil weeps through casting defects or fracture lines; welding is a temporary gamble on a production unit.
- Bores worn oval or oversize — beyond economic sleeve/re-bore, the geometry that holds CD and mesh is gone.
- Duty has changed — higher load, continuous duty where the old box was intermittent, or a ratio that no longer matches the process.
- Obsolete make / long spare chain — original spares months away, drawings missing, and the line cannot wait. A drop-in matched to mounting and shafts is often faster than hunting brand-coded parts.
- Repeated rebuilds — if the same unit has been opened several times for the same wear mode, total cost of downtime may already exceed a new matched unit.
Cost and downtime logic (no prices — framework only)
Compare three clocks, not only three invoices:
- Strip and assess time — required for an honest repair quote anyway.
- Parts lead time — matched set vs complete new gearbox vs waiting on an obsolete catalogue code.
- Install risk — repair reuses known mounting; a poorly specified “catalogue nearest size” can cost days of foundation and coupling rework.
A cheap repair that returns a mismatched worm and old wheel often fails early. A full new unit that does not match CD or foot print is not a bargain either. Measure first.
The matched-set caveat
Do not fit a new phosphor bronze wheel against a worn worm, or a new worm against a polished-out wheel. Sliding contact on worms wears both members into a shared pattern. Anand Gears supplies worm and wheel as a matched pair for this reason — see the spares page and the matched-set engineering note on our blog when you order gears only.
Obsolete and any-make situations
Brand name is optional data. What matters is CD, ratio, shafts, and mounting in mm. We reverse-engineer from sample when drawings are missing and build a unit that bolts down on the existing pattern — the same service described under replacement of any make.
Quick decision table
- Housing good + mesh bad → repair with matched set + bearings/seals.
- Housing bad → replace (drop-in).
- Housing good + process needs new ratio/orientation → often replace or special, not a simple re-mesh.
- Unsure → send photos and measurements; ask for rebuild vs new options on one quote.
Related: Replacement & Repair · Worm Gear Sets & Spares · How to Measure for Replacement · Contact