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Onan B48M -- What Are These Sounds? ... What Do They Mean?

onan b48m sounds case 448 valve train bearings

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#16 Case448 OFFLINE  

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Posted March 06, 2016 - 04:51 PM

Discovery #1:

 

Pulled the camshaft out, and it was basically as I suspected.

 

Rear camshaft bearing going away, metal shavings behind cam, trapped between cam end and block plug. "U" shaped area of rear cam bearing around push rod for points (as I suspect it should be), however, the oil hole in the rear cam bearing is positioned on the drivers side of motor, and is *NOT* matched up with any oil hole in the block, so rear cam bearing was not getting any oil. Rear end of camshaft shows about .001 metal removed on back half of overall bearing depth. Camshaft is shot.

 

Front of block, surrounding camshaft hole behind camshaft thrust washer, worn back about 1/16" -- I'm assuming this surface should be flat (same as the rest of the machined sueface on front of block.) Looks like the camshaft was "walking" back in block, towards the rear, I'm not sure why. So, block is probably shot.

 

Crankshaft still in block, not sure if I even need to look that far at this point.

 

Any help / suggestions appreciated.

 

Thanks all --

 

Dave


Edited by Case448, March 06, 2016 - 04:53 PM.


#17 KennyP ONLINE  

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Posted March 06, 2016 - 04:53 PM

Look for a PM!



#18 Case448 OFFLINE  

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Posted March 06, 2016 - 04:55 PM

Look for a PM!

 

PM = parts machine?



#19 MH81 ONLINE  

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Posted March 06, 2016 - 05:04 PM

PM = parts machine?


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