A replacement motor can match power and speed yet still place the shaft at a different elevation or axial position. The correction affects more than coupling alignment.
| Interface | Evidence | Stop when |
|---|---|---|
| Shaft centreline | Survey and dimensioned overlay | Height or axial position is assumed |
| Base support | Adapter/soleplate calculation and drawing | Load rests on an improvised shim stack |
| Hold-downs | Bolt size, edge distance and access | Slots or new holes weaken the support |
| Coupling | Hub engagement, gap and alignment limits | Shaft extension or key does not match |
Approve the installed load path
Check motor mass, centre of gravity, base stiffness and lifting access. A raised motor changes bolt geometry and may reduce access to drains, terminal boxes or cooling air.
Measure soft foot before coupling alignment. Record final shim locations and thicknesses, bolt torque, cold alignment and any thermal-growth targets. Preserve the as-built drawing so the next replacement does not repeat the survey.
Related reading: motor mounting arrangements and shaft alignment basics.