xring1 2 #1 Posted April 30, 2010 I just picked up my 3rd WH. A 520H with a really nice 48" deck. The tractor is in good overall condition but a few loose bolts etc. Not maintained real well I figure but for $100 who is going to complain. At least the oil in the engine and rear are clean. The engine was locked up but with some persuasion I got it to free up...sort of. If I get it loose with a pipe wrench it will sometimes roll over a few times before it locks up again on the starter. I notice that rolling it over with a wrench that sometimes you hear a "clank" in the crank area like a rod end dropping so I think it is a broken rod. Soooo the question is...is there an easy way to look into the engine? I have not looked for an engine diagram yet but it looks like one might be able to open up the case from the PTO side. Any help appreciated........... Share this post Link to post Share on other sites
sorekiwi 761 #2 Posted May 1, 2010 Soooo the question is...is there an easy way to look into the engine? I have not looked for an engine diagram yet but it looks like one might be able to open up the case from the PTO side. Any help appreciated........... Whatever it is, it doesnt sound good. I think you could remove the cover on the PTO side of the engine, with the engine in place, but I doubt that you will be able to see much, the hole is not much bigger than the webs on the crankshaft. On the other hand, pulling the motor out isnt that bad, and once its out its a simple matter to roll it up on the flywheel and remove the 4 bolts that hold the oil pan on. Here's what a broken Onan rod looks like, mine ran fine like this, smooth, no miss at all, just no power: Share this post Link to post Share on other sites
xring1 2 #3 Posted May 1, 2010 Soooo the question is...is there an easy way to look into the engine? I have not looked for an engine diagram yet but it looks like one might be able to open up the case from the PTO side. Any help appreciated........... Whatever it is, it doesnt sound good. I think you could remove the cover on the PTO side of the engine, with the engine in place, but I doubt that you will be able to see much, the hole is not much bigger than the webs on the crankshaft. On the other hand, pulling the motor out isnt that bad, and once its out its a simple matter to roll it up on the flywheel and remove the 4 bolts that hold the oil pan on. Here's what a broken Onan rod looks like, mine ran fine like this, smooth, no miss at all, just no power: Hmmmmm that is what they call catastrophic failure. I have a piston that came out of a Cessna 172 I was flying that has a valve and about 1 1/2" of stem embedded/melted into it I will probably pull the engine and remove the oil pan. Hopefully if it is a rod I will get away with just replacing it. Share this post Link to post Share on other sites
sorekiwi 761 #4 Posted May 1, 2010 I was actually pleased to find a broken rod in mine. I bought it thinking it had a bad valve seat, and it seems that sometimes that is a hard issue to fix. The broken rod was a straight forward fix. Glad I wasnt in that Cessna... Share this post Link to post Share on other sites
xring1 2 #5 Posted May 1, 2010 I was actually pleased to find a broken rod in mine. I bought it thinking it had a bad valve seat, and it seems that sometimes that is a hard issue to fix. The broken rod was a straight forward fix. Glad I wasnt in that Cessna... yeh it got real interesting real quick. Happened on take off at about 1800 feet. managed to get turned around and back on the runway did you have to do anything besides replace the rod? Share this post Link to post Share on other sites
xring1 2 #6 Posted May 2, 2010 I drained the oil and flushed the case with an oil gas mix thru a fine screen and there were no metal bits so I guess it did not explode very bad Share this post Link to post Share on other sites
Save Old Iron 1,564 #7 Posted May 2, 2010 You could remove the spark plug and insert a piece of wooden dowel down onto the piston. Turn the crank a little and if the dowel doesn't move, there is no connection from the crank to the piston. So a broken rod would be a likely candidate. Share this post Link to post Share on other sites
sorekiwi 761 #8 Posted May 2, 2010 did you have to do anything besides replace the rod? I actually havent got it running again yet, just another of my unfinished projects I ended up picking up another engine (that did have a bad valve seat) and used the rods and pistons out of that. There are a couple of different rods used in these, so I wanted to use a matching pair. My crank had a bit of aluminum build up on the journal, but that polished off OK. While I had the two engines sitting there in a million pieces, I kinda picked the best looking pieces to use. The block itself showed no damage at all. Then again mine didnt have any nasty clanking noises when I turned it over either. Have you seen this thread? http://www.mytractorforum.com/showthread.php?t=91204 A ton of good information in there, a lot of tips and a lot of photo's as well. Edit: I forgot to mention that MTF has a better (downloadable) Onan Manual in their reference library. Its the John Deere dealer version, and has a lot of stuff in it that the Wheelhorse version doesnt have. Share this post Link to post Share on other sites
