# SDR 99ZZZX589

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 20, 1998
- Submitted: March 26, 2000
- Operation: General aviation
- Aircraft: [N2585W](https://openairdocs.org/aircraft/N2585W), registered now
- Make and model: Mooney M20E
- Registry model: [Mooney M20E](https://openairdocs.org/model/mooney-m20e) (OpenAirDocs)
- Aircraft serial: 940
- Engine: Lyc IO360A1A
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Push Rod
- Part number: 73457
- Condition: Worn
- Location: Engine
- Stage of operation: IN
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/99ZZZX589

## Discrepancy

THIS ENGINE WAS DISASSEMBLED FOR REPLACEMENT OF 4 CYLINDERS DUE TO LOW COMPRESSION.  IT HAD 125 HOURS SMOH BY LYCOMING.  THE NR 1 ROCKER ARMS WERE FOUND SWITCHED.  THE EXHAUST ROCKER IN THE INTAKE POSITION DID NOT DAMAGE, HOWEVER, THE INTAKE ROCKER WORE THE PUSH ROD SEVERELY ON THE EXHAUST SIDE FROM CONTACT ABOUT .50 INCH FROM THE END.  THE WALL OF THE PUSH ROD WAS NEARLY WORN THROUGH.  THE INTAKE ROCKER HAS A RAISED AREA ON THE BODY TO PREVENT THIS MISTAKE, BUT THESE CYLINDERS ARE MACHINED DEEPLY ENOUGH TO ALLOW THE INTAKE ROCKER TO FIT IN THE EXHAUST POSITION.

---
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.