2. Pivoting shoe surface and seat in retaining ring
3. Seal ring bore or end plates
4. The shoe thickness at the pivot point or across ball and socket; all shoes should be within 0.0005% of the same thickness
While being inspected， the following checks should be made:
1. All leading edges of shoes must have a uniform radius for the full length across the shoe. File the radii if necessary to obtain proper size.
2. Light scratches in the babbitt face do not necessarily require shoereplacement. If no wear is detected， scrape lightly with a sharp straight-edged scraper (plate type) to remove any upsetting caused by scratches.
3. Shoes should be replaced as sets only if:
a. Radial clearance has increased more than 11.2 mils over nominal design clearance.
b. Leading or lagging edges of shoes show signs of wear.
4. The tilting-pad and support-ball combination spare parts should belapped together， making them an integral unit. When a new or usedbearing is disassembled for cleaning and inspection， care should be taken not to mix the tilting-pad and support-ball combinations.
5. On
reassembly， care should be taken to return the tilting-pad and support-ball combination to the original location in the support ring. Changes in clearance and concentricity can result if the tilting-pad and support-ball combination is not returned to the same location. An eccentricity of as little as one mil can cause severe vibration problems.
.learance .hec.s
1. Check housing OD and ID to be sure it is round.
2. Check
bore and face-end plates for nickededges， deep scratches， or sco-ring. Stone or scrape if necessary， and polish with very fine aluminum oxide polishing paper.
3. Check parting-line surfaces for full contact. Stone or lap if burrs or raised edges exist.
4. Check
pivoting surfaces of shoe and housing ring for scratches， scor-ing， or erosion. Stone if necessary.
5. For
tilting-pad bearings， blue-shoe the pivot surface， and check for contact area and position. The contacting surface must be in the center only and at the bottom portion of the pivot bore in the retainer.
6. Check to be sure that pins do not bottom-out in pads.
.. For ball-and-socketdesigns， check to be sure the ball seats properly and solidly in the counter bore.
8. Check for shaft clearance as follows:
a. Select a stub mandrel in which the minimum diameter is the journal diameter plus minimum desired clearance (about 11.2 mil per inch of shaft diameter) and the larger diameter is journal diameter plus desired clearance (about 2 mils per inch of shaft diameter).
b. Assemble the bearing halves.
c. Slip the assembled bearing over the smaller diameter of the man-drel.
d. Tap the bearing lightly on the back of the housing and slide the bearing down on the next larger diameter.
e. The mandrel should be rotated and the OD of housing indi-cated.
Thrust-8earing Failure
A thrust-bearing failure is one of the worst things that can happen to amachine， since it often wrecks themachine， sometimes completely. To evaluate the reliability of a thrust-bearingarrangement， we must first consider how a failure is initiated and evaluate the merits of the various designs.
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