Bearing Housing Sleeves for Motor End Bells

What is a bearing housing sleeve, and when does a bore need one?

A motor’s bearings sit in bores in the end bells, which are also called end brackets or end shields. When one of those bores wears past the size the bearing needs, re-sleeving a worn bearing housing bore brings it back. The housing is bored oversize, the bearing housing sleeve is pressed or shrunk in, and the sleeve’s bore is turned to the bearing size (source 7). Motor end bell sleeve, end bracket sleeve and bearing housing sleeve are three names for the same part. The boring, the pressing and the finishing are yours. The sleeve is what MI CNC Parts supplies, and the pump and motor repair parts page shows where it sits among the other motor parts.

EASA’s ANSI-recognized repair practice, AR100, says that bearing housing and shaft bearing fits “should be measured and compared” to the machine maker’s specifications, and that “Any fits that are not within tolerance should be restored” (source 1). A sleeve is one way to restore a housing fit. Its print is quoted like any other turned part; CNC turning covers the diameters and lengths.

Three neighbors get mixed up with it. A sleeve over a turned-down motor journal is a shaft repair sleeve, covered on the hub. A sleeve on a pump shaft is one of the pump shaft sleeves, and the rings in a pump casing are wear rings. The bushing in a plain sleeve bearing is a different part again, on custom bushings.

Why the bore wears: creep, fretting and a loose fit

In a motor the shaft turns and the outer ring of the bearing stays put, so the usual arrangement is “a press fit on the shaft and a loose fit on the housing,” in NTN’s fit guidance (source 2). AR100’s bearing tables agree: they list the shaft fits as interference and the housing fits as clearance (source 1). NTN adds that “too loose of a fit may allow the bearing ring to slip or creep on the shaft or in the housing,” and that creep “can cause excessive wear or vibration and in the worst cases lead to ring fracture or bearing seizure” (source 2).

NSK defines creep as the phenomenon “where relative slippage occurs between fitting surfaces and thereby creates a clearance between them,” and lists its cause as “Insufficient interference or loose fit” (source 3). Richard Knotek of Motion Industries writes in Plant Engineering that “Fretting-corrosion occurs when there is movement between a bearing ring and shaft or housing because the fit is too loose,” and that “In extreme cases of inadequate fit, the outer or inner ring may turn or creep, resulting in galling of the surfaces” (source 4).

Reliability Solutions puts the housing side plainly: “Housings distort and wear oval” (source 5). A new outer ring dropped into a bore that has already opened up meets the same loose fit, so the bore is restored first, and the same article says “Worn or oval housing bores can be bored and sleeved” (source 5).

What a bearing housing sleeve print carries

A sleeve has two fits on one part. Its outside diameter goes into the housing you bored, with the interference you choose for that bore. Its own bore takes the bearing’s outside diameter, and the bearing sits in it the way it sat in the original housing.

The print names the outside diameter and how much interference it should have in the bore you cut, the sleeve bore, the length, and any shoulder or flange. Add the runout you want between bore and outside diameter. Position, perpendicularity and runout callouts are quoted from the print. Mark which diameters are critical, because how tight each one is held is quoted from the print too. Typical machined tolerance is ±0.005 in, ±0.001 in on critical turned diameters, and down to ±0.0002 in on wire-EDM and other finished features; ground features are quoted to ±0.0001 in.

Finished bore, or stock left on it?

The print says which, and the quote follows the print. Catalog sleeves show why some repairs want stock left on the bore. Shaver-Kudell answers its own question, “Why is the I.D. of the sleeve not finished?”, by pointing at pressing problems, for example dirt between sleeve and housing or a sleeve pressed in crooked: “The I.D. of the sleeve will change or distort. If this happens, bearing failure is inevitable” (source 6). Whichever the print names, state the bore size and tolerance, or the amount of stock to leave, on the drawing or in the part description field of the quote form.

How the sleeve goes in, pressed, shrunk or glued, is your call (sources 6 and 7), and it shapes the print. If your method changes the length, a lead-in chamfer or the interference, name the method in the part description.

Sleeve material, hardness and finish

Wescap’s catalog sleeves are steel (source 7), and the grades a print can name are on the steel page. Other alloys and plastics quoted on request. Name the grade on the print.

Hardness can be arranged and quoted. A finish called out on the print is quoted with the part.

What to send: a print, or a new sample sleeve

A print is the fastest start. Send the outside diameter, the interference you want in the bored housing, the bore, length, shoulder or flange, the material, and how many sleeves you use in a year. Files: any file type; STEP + PDF ideal. Add the motor make and model when it helps place the part.

With no print, send a new sample sleeve of the right type. Send a new part, not the worn one. Wear changes the sizes that matter. The sample gets measured and drawn as part of reverse engineering. The sample ships back with the parts. If you can, add a new bearing of the size you fit. A new mating part helps confirm the fit. It ships back with the parts.

Reordering the sizes you sleeve every month

When you bore housings to a set size for each bearing number, the sleeve for that number repeats from job to job. AR100’s ball bearing table gives a bearing outside diameter and a housing bore for each bearing number (source 1). A family of sleeves gets one line per size, and one purchase order can carry sleeves for several bearing numbers, each size at its own quantity.

Ask for more than one quantity, such as 1, 25 and 100, and the quote shows each. A year’s usage can be quoted as a blanket order delivered in releases. Price, release schedule and lead time per release are set in the quote. Reorders at the same revision: send the last quote or PO number and it’s requoted. On a sleeve started from a sample, the drawing is quoted as its own line on the first order, and reorders come off that same drawing. No minimum: one piece to production runs of 10,000. Where the price breaks fall is on small-batch CNC machining.

Lead time, quotes and what comes with the sleeve

Quotes come back in 24-48 hours. Rush: 1-2 weeks. Standard: 4-6 weeks (typical). Extended: 6-8 weeks, for jobs that aren't time-sensitive.

Every part is inspected against your print before it ships. If a part doesn’t match the print, it’s remade or credited. Parts are supplied as replacements by fit and dimensions. No OEM logos, part numbers or markings are copied.

Sources

Quoted passages on this page come from the following, all accessed 28 September 2026. Where anything here differs from your print, the print governs.

1. EASA, “ANSI/EASA Standard AR100-2025: Recommended Practice for the Repair of Rotating Electrical Apparatus,” EASA, 2025: easa.com/resources/resource-library/ansieasa-standard-ar100-2025-recommended-practice-for-the-repair-of-rotating-electrical-apparatus (section 2.2.1, section 2.4.1 and Table 2-6: housing fits restored; shaft fits interference, housing fits clearance; a housing bore for each bearing number).

2. NTN Bearing Corporation of America, “Bearings With Shaft & Housing Fits,” NTN Americas technical resources, undated, ntnamericas.com/technical-resources/shaft-housing-fits/ (loose housing fit for a rotating shaft; creep; aluminum housings).

3. NSK Americas, “Creep,” Damage by Type, undated, nsk.com/am-en/tools-resources/bearings/troubleshooting/damage-by-type/creep/ (definition and cause of creep).

4. Richard R. Knotek, “Diagnose bearing failures beyond root cause analysis,” Plant Engineering, 3 November 2016: plantengineering.com/diagnose-bearing-failures-beyond-root-cause-analysis/ (fretting-corrosion from a loose fit; outer ring creep and galling; measuring mating components).

5. Reliability Solutions, “Bearing Fits and Tolerances: Why Installation Errors Destroy Bearings Early,” 5 August 2026: reliabilitysolutions.net/resources/blog/bearing-fits-and-tolerances/ (worn and oval housings; bore and sleeve repair; measuring a housing bore).

6. Shaver-Kudell, “Eze-Sleeve Information and Installation Instructions,” undated, shaverkudell.ca/wp/products/eze-sleeves-list/the-original-cast-iron-series/eze-sleeve-information-and-installation-instructions (why the sleeve bore is left unfinished; pressing or freezing a sleeve in; extended lip cut off after pressing).

7. Wescap, “Bearing housings repair sleeves,” undated, wescap.eu/bearing-housings-repair-sleeves (steel catalog sleeves; gluing or pressing; sleeve turned to the bearing size; protruding part turned away).