Detroit Diesel 4000 Series, Service Manual, Page: 478 / 2706

SERIES 4000 12/16V SERVICE MANUAL
C 032.05.08 – INSPECTION AND REPAIR
Perform the following steps to inspect and repair the flywheel:
1. Clean and inspect all components.
2. Using the magnetic crack-testing method with fluorescent powder, inspect drive hub, ring
gear and hex bolts of flex coupling for cracks.
[a] If cracks are found, replace cracked component.
[b] If no cracks are found, continue inspection.
3. Visually inspect mating surfaces on flex coupling for evenness, wear, scoring and
indentations.
[a] If mating surfaces are uneven or show wear, scoring or indentations, recondition
affected component as necessary.
[b] If no unevenness, wear, scoring or indentations are found, continue inspection.
4. Visually inspect all sealing, mating and bearing surfaces on drive hub for wear, scoring
and indentations.
[a] If minor wear, scoring or indentations are found, remove by rubbing down with
oilstone or emery cloth.
[b] If damage cannot be removed with oilstone or emery cloth, replace drive hub as
necessary.
[c] If no wear, scoring or indentations are found, continue inspection.
5. Visually inspect taper surfaces of drive hub for scoring and damage.
[a] If minor scoring or damage is found, polish with emery cloth.
[b] If no scoring or damage is found, continue inspection.
6. Check taper 1:50 with taper gage.
[a] If taper bore is oversized, replace drive hub.
[b] If taper bore is not oversized, continue inspection.
7. Visually inspect threads of hex bolts for flex coupling.
[a] If threads are not in perfect condition, replace hex bolts as necessary.
[b] If threads are in perfect condition, continue inspection.
8. Visually inspect threads of expansion bore.
[a] If threads of expansion bore are not in perfect condition, rechase threads as necessary.
[b] If threads are in perfect condition and show ease of movement, continue inspection.
9. Inspect thread in drive hub for condition and ease of movement.
[a] If threads of drive hub are not in perfect condition or do not show ease of movement,
rechase threads as necessary.
All information subject to change without notice.
C -332
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