General Electric Service Bulletin (SB) CF34-72-0252 replaces the #5 bearing that was introduced on newer production engines, starting with engine S/N 950333, or with the incorporation of SB 72-0176. The #5 bearing, P/N 5042T13P04, was redesigned to increase the internal radial clearance. This increased clearance has now shown to be susceptible to higher engine vibrations.
The new bearing, P/N 5042T13P06, reduces the internal radial clearance. GE recommends that this category 6 SB be accomplished at next exposure.
If you are experiencing INTERMITTENT vibration levels that are significantly higher than normal at the higher power settings, please contact Duncan Aviation for further investigation.
For more information about this Service Bulletin, contact me anytime.
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