# SDR NX422026020600002

- 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
- System (JASC): [8520 · Reciprocating Engine Power Section](https://openairdocs.org/jasc/8520)
- Part: Stud
- Part number: 76220
- Part serial: L3964351E
- Condition: Displaced
- Location: Engine
- Part time: 2,450 hours
- Stage of operation: UK
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/NX422026020600002

## Discrepancy

ON DISASSEMBLY FOR ITS 1ST OVERHAUL, DAMAGE FOUND ON 2 OF THRU STUDS.  DAMAGE APPEARS TO BE DISPLACED STEEL UNDER THREADED PORTION ON SHOULDER OF THRU STUDS. ON 1 THRU STUD.  DAMAGE IS SEVERE WITH DISPLACED METAL FROM SMALLER NECKED DOWN PORTION OF STUD UP TO THE THICKER PORTION OF STUD UNDER THREADS. OTHER STUD IS LESS SEVERE BUT HAS DAMAGE IN SAME AREA. LT CRANKCASE OF  ENGINE ALSO HAS DAMAGE TO  INSIDE OF  THRU STUD BORE LOCATIONS. A 2ND FIRST RUN ENG WAS DISCOVERED TO HAVE SIMILAR DAMAGE TO 1 THRU STUD BORE LOCATION  & 2 OF THRU STUDS. PREVIOUSLY A REPORT HAD BEEN SUBMITTED IN DECEMBER ON A THIRD ENGINE FOR THE SAME LT CRANCASE DAMAGE TO ALL 4 OF THRU STUD BORES.   UPON CLOSER INSPECTION OF THIS 3RD ENG,  HAVE FOUND SOME MINOR DAMAGE TO 1 OF THRU STUDS IN  SAME LOCATION.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.