# SDR NX422026020600001

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 2, 2026
- Submitted: February 6, 2026
- Operation: General aviation
- Filed by: [Embry-Riddle Aeronautical University Inc, repair station NX42404M](https://openairdocs.org/faa-repair-station/NX42404M/embry-riddle-aeronautical-university-inc.md) (OpenAirDocs)
- Aircraft: [N963ER](https://openairdocs.org/aircraft/N963ER), registered now
- Make and model: Cessna 172S
- Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (OpenAirDocs)
- Engine: Lyc IO360L2A
- Engine time: 2,450 hours
- System (JASC): [8520 · Reciprocating Engine Power Section](https://openairdocs.org/jasc/8520)
- Part: Crankcase
- Part number: LW184025
- Part serial: L3964351E
- Condition: Gouged
- Location: Engine
- Part time: 2,450 hours
- Stage of operation: NR
- How discovered: V
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/NX422026020600001

## Discrepancy

UPON DISASSEMBLY FOR ITS FIRST OVERHAUL, DAMAGE WAS FOUND ON THE LEFT HAND CRANCASE ON ALL 4 OF THE FLOATING THRU STUD LOCATIONS. THE DAMAGE APPEARS TO BE A GOUGE WITH DISPLACED METAL JUST UNDER THE CYLINDER PAD INSIDE THE THRU STUD BORES. IN ADDITION, 2 OF THE THRU STUDS HAD DISPLACED STEEL UNDER THE THREADED PORTION ON THE SHOULDER OF THE THRU STUDS. SEE SDR CONTROL# NX422026020600002 FOR DAMAGE TO THRU STUDS. A SECOND FIRST RUN ENGINE S/N# L-39625-51E WAS DISCOVERED TO HAVE SIMILAR DAMAGE TO 1 THRU STUD BORE LOCATION (SEE SDR CONTROL# NX422026020600003) AND 2 OF THE THRU STUDS (SEE SDR CONTROL# NX422026020600004). PREVIOUSLY A REPORT HAD BEEN SUBMITTED IN DECEMBER ON A THIRD ENGINE S/N# L-39621-51E FOR THE SAME LEFT HAND CRANCASE DAMAGE TO ALL 4 OF THE THRU STUD BORES. UNFORTUNATELY, I CANNOT FIND THE CONTROL# FOR THIS REPORT. UPON CLOSER INSPECTION OF THIS THIRD ENGINE I HAVE FOUND SOME MINOR DAMAGE TO 1 OF THE THRU STUDS IN THE SAME LOCATION AS THOSE LISTED IN THE REPORTS ABOVE.

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