Integrated Bearing Maintenance Task: Removal, Inspection, Installation, and Documentation

Integrated Bearing Maintenance: Why the Full Cycle Matters

A bearing does not fail in isolation. Contaminated grease, a shaft seat that is 0.001 in. undersized, a pillow block torqued without alignment, a technician who skipped lockout — any one of these turns a routine task into a safety event or a premature failure. Today's lab brings every skill from this course together into a single, unbroken maintenance cycle. You will perform lockout/tagout, remove bearings correctly, measure seats and bores, select replacements from a catalog, install using the right method, lubricate to a calculated quantity, verify alignment, run the assembly under supervision, take condition readings, and submit a professional work order. That sequence is exactly what industry expects of a certificated maintenance technician.

Step 1 — LOTO Before You Touch Anything

Before you open a panel or loosen a fastener, apply your facility's written lockout/tagout procedure to every energy source on the assembly: electrical disconnect, pneumatic supply, hydraulic line, and any stored mechanical energy (springs, elevated loads). Verify zero energy state by attempting to start the machine and checking for residual pressure with a gauge. A single LOTO violation during this lab results in an automatic repeat of the entire assessment — no exceptions. This mirrors industry: OSHA 29 CFR 1910.147 makes LOTO the legal baseline, and employers treat violations as terminable offenses.

PPE for disassembly: safety glasses, cut-resistant gloves when handling bearing edges and snap rings, and steel-toed footwear throughout. When using the induction heater, add heat-resistant gloves.

Step 2 — Disassembly and Parts Lay-Out

Work methodically. Label each bearing position (Position 1, 2, 3…) before you remove anything. Photograph or sketch the assembly orientation so you can restore it correctly. Use the assigned puller or press tooling for each position — never strike a bearing with a steel hammer directly on the race, and never apply puller force through the rolling elements. Lay every part on a clean, lint-free mat in the order removed. Note any visible defects: discoloration, pitting, spalling, cage damage, lubricant color or smell.

The instructor has seeded one defect into this assembly. Common seeded defects include the wrong lubricant type, grease contaminated with water or metallic particles, or a pillow block that is misaligned by a measurable amount. Your job is to find it, correct it, and document it — not to be told what it is.

Step 3 — Measurement: Shaft Seats and Housing Bores

Clean each shaft seat and housing bore before measuring. Use a calibrated micrometer for shaft OD and a bore gauge (set against a known ring gauge or micrometer) for housing ID. Take three readings at 120° intervals and average them. Record every reading on your work order. The pass criterion for this lab is ±0.0002 in. of the assembly reference drawing. Out-of-tolerance seats must be flagged and reported; do not install a bearing on a damaged seat without instructor direction.

Shaft fit is typically an interference fit (bearing ID slightly smaller than shaft OD for inner ring rotation), while many housed-unit housings use a transition or light clearance fit on the outer ring. Confirm the fit class from the manufacturer's catalog before selecting the installation method.

Step 4 — Bearing Selection and Installation

Use the bearing supply crib catalog to select replacements that match the required bore, OD, width, load rating, and seal type for each position. Record the part number and catalog page on your work order.

Thermal installation (shaft bearing): Heat the bearing in the induction heater to the manufacturer's recommended temperature — typically in the 200–250 °F range; never exceed 250 °F (121 °C), which is the general safe limit to avoid altering ring hardness. Verify temperature with an infrared thermometer, not by guesswork. Use heat-resistant gloves and slide the bearing to its shoulder immediately; hold it in place for 30–60 seconds as it cools and contracts onto the shaft.

Press installation (housing bearing): Use a properly sized installation sleeve that bears only on the outer ring for outer-ring-only fits, or only on the inner ring for inner-ring-only fits. Apply force steadily through the hydraulic press — never impact force on a race through the rolling elements.

Step 5 — Lubrication to a Calculated Quantity

Apply grease using the standard volume formula: G = 0.114 × D × B, where G is the grease quantity in ounces, D is the bearing OD in inches, and B is the bearing width in inches. Fill the bearing cavity and purge lines to approximately one-third to one-half of housing free space for most grease-lubricated housings — over-greasing is as harmful as under-greasing because it elevates operating temperature and can damage seals. Record lubricant type, NLGI grade, and quantity applied on the work order.

Step 6 — Alignment Verification

After reassembly, mount a dial indicator on a magnetic base and check shaft runout and coupling alignment. Parallel and angular misalignment must both be within the coupling manufacturer's tolerance. Use shim stock to correct vertical offset. Document indicator readings before and after any correction.

Step 7 — Run Check and Condition Monitoring

With the instructor present, re-energize the assembly following your facility's re-energization procedure (LOTO devices removed by the person who applied them). Allow the assembly to reach operating temperature, then record vibration amplitude with the vibration pen and surface temperature with the infrared thermometer at each bearing position. Compare readings to the baseline values on the work order form. Elevated temperature (typically more than 40 °F above ambient at steady state for a correctly lubricated bearing) or abnormal vibration indicates a problem. Identify whether the seeded defect was corrected or is still present, and document your conclusion with evidence.

Completing the Maintenance Work Order

A professional work order is your proof of work. It must include: equipment ID, date, technician name, LOTO log reference, measurements taken, bearing part numbers installed, lubricant type and quantity, alignment readings, run-check readings, failure analysis of the removed defective bearing (failure mode, probable cause, corrective action), and your signature. Incomplete documentation is a competency failure in this trade.