Figure this out , I`m confused

[Bt Doctur]

This is from a 351C inboard motor . Needed rear main seal replaced and during reassembly this was found. All 6 flywheel bolts are exactly the same. Never seen anything like this .

 

[racerone]

Poor quality material ???---Chinesium parts ?-----And they appear to be stretched from over torque

 

[Scott Danforth]

Im going with buy 6 new bolts. looks like you were lucky to get them out

 

[Bt Doctur]

removal was not that difficult even with the breaker bar 1/4 to 1/2 turn and they were free. All agree they were stretched but how much torque do you need to install flywheel bolts in a crankshaft spec is 75-85 and that cant stretch a bolt like that

 

[Scott Danforth]

my guess is someone prior used a burp gun

 

[flashback]

my guess is someone prior used a burp gun

and a darned accurate burp gun. I would have thought the bolts would have snapped..

 

[Scott06]

my guess is someone prior used a burp gun

And a big one at that

 

[QBhoy]

Those bolts have been stretched with a fair amount of tightening force. When a bolt of a certain tensile strength is over tightened and the threads manage to hold on…the bolt has no option but to stretch, break or shear threads. My thinking anyway !

 

[Searay205]

Someone reused bolts that shouldn't have been reused and they yielded.