randyh 4 #1 Posted January 4, 2015 Have a 518H just bought with seized engine. We disassembled it this weekend. Found broken connecting rod, and piston. Bearing seized on flywheel side of engine. Some aluminum from connecting rod melted onto crank. Looking into replacement parts. One source mentioned matching casting numbers on rod and piston. Is this a critical issue. Any other coments welcome Share this post Link to post Share on other sites
Desko 624 #2 Posted January 4, 2015 Yes but you can ask boomers influence he is the onan parts master and he'll set you in the right direction hes a member here i cant set a link im on my mobile but someone will get it Share this post Link to post Share on other sites
AMC RULES 37,196 #3 Posted January 4, 2015 http://boomersonanparts.com/ Share this post Link to post Share on other sites
Desko 624 #4 Posted January 4, 2015 AMC thanks for posting the link Share this post Link to post Share on other sites
randyh 4 #5 Posted January 4, 2015 thanks both of you I sent an email off to him Share this post Link to post Share on other sites
wheel-mule 46 #6 Posted January 4, 2015 To remove the aluminum from the crank soak it in bleach.Will discolor crank but will loosen the aluminum without damage to the crank.Than mic crank . Share this post Link to post Share on other sites
sorekiwi 761 #7 Posted January 5, 2015 Boomer will give you the details, but there are several different rods used in the Onans. (Possibly pistons too). When I patched mine up (bought with a broken rod) I made sure to replace both rods and both pistons to retain balance in the engine. I managed to find an engine that had lost the valve seat, so I used those internals inside my own block. Share this post Link to post Share on other sites
randyh 4 #8 Posted January 5, 2015 Talked to Boomer and got a lot of good information. I need to finish dis assembly and further diagnose what needs to be done. Thanks for the input Share this post Link to post Share on other sites
