SDR 97ZZZX181

Service difficulty report · Stud

Difficulty date
December 26, 1996
Submitted
March 26, 2000
Operation
General aviation
Engine
Cont TSIO360EB
Part
Stud
Part number
6436511
Condition
Stretch
Location
Cyl Hold Down
Part time
1,762 hours
Stage of operation
IN
Nature of condition
O
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

DURING THE COURSE OF A NORMAL ENG OVERHAUL, IT WAS FOUND THAT ABOUT ONE-THIRD OF THE CYL DECK STUDS WOULD NOT HOLD SPECIFIED TORQUE WITHOUT STRETCHING. THE STUDS ARE A NEWER 'NECKED DOWN' DESIGN. THE MECH REPLACED ALL CYL DECK STUDS WITH AN OLDER STRAIGHT DESIGN AND TORQUED THEM TO SPEC. IT IS CRITICAL THAT THESE STUDS HOLD TORQUE. SUBMITTER STATED IT IS LIKELY THAT THE REASON THAT THE STUDS WOULD NOT HOLD TORQUE IS THAT THEY WERE NOT MFG WITH THE CORRECT HARDNESS. RECOMMENDED THAT ALL CYL DECK STUDS BE CHECKED AT THE SPECIFIED TORQUE BEFORE FINAL ASSEMBLY AT OVERHAUL OR AT A CYLINDER CHANGE.