Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

Failed connecting rods


Brettw

Recommended Posts

So this is interesting. Picked up a Sunstar with a bad M18 in it. Pulled it apart, and as expected it had a broken rod. Fortunately, other internal damage was virtually non-existent. Anyway, on e-bay I see a set of brand new M18 rods and pistons, with the rings. Some outfit out East took a NOS short block and was parting it out. (I screwed up and missed out on the jugs, brand new with the valves, breather assembly, etc. the pair went for $162)

Anyway, I needed to clean up the crank a bit. (Archived post helped, thanks once again to Al, God rest his soul) So after I cleaned it up, I tried quickly bolting the remaining existing rod onto the crank just to feel for fit, just snugged up, not torqued. Couldn't budge it. Moved it to the "good" crank journal. Couldn't budge it. So my take is, this is the perfect example of catching the rod just prior to it completely seizing and grenade-ing too. The other one went first and "saved" this one. Placed one of the new rods assemblies on the crank and it's perfect.

I can see a ring around the center of the existing rod where the oil journal should be feeding it. It doesn't feel with the fingernail scratch like there is any material there, but it must build up or something because it is tight.

Some of you with more experience regarding this might have more insight.

Link to comment
Share on other sites

It may just be distorted from excess heat in a failing engine?? You are right though, that it should have swung freely on the rod journal. Good catch. Tim

Link to comment
Share on other sites

I was watching the block, to replace the block on the M18 I have with the hole in it.................

Cannot believe I lost track of time and missed bidding, went for $83 :o:O

Link to comment
Share on other sites

Good thing it did stop where it did. Someone had me fix a briggs 16twin where he kept running it all summer with one rod gone. Until the stub wedged into the case a certain way as to crack a hole in the side, there were 35 separate peices of rodsm00

Link to comment
Share on other sites

quote:Originally posted by mikeman

What are you using to seal the case back together?


id="quote">
id="quote">I'm not sure what Brett will use, but I just finished put a KT17 back together. I use the blue RTV silicone to seal up the crankcase. I have never had a problem with it and no leaks.
Link to comment
Share on other sites

The newer magnums do not use gaskets other than the closing plate, and even then some do not use a gasket there. I use black RTV silicone per the Kohler service manual.

Link to comment
Share on other sites

Thanks Brett, I bought an E-bay Deutz allis 1918 with 1 broken rod this winter too. I will need to do the same to it. Thats a bummer you missed the new parts sale.

Are those prone to rod failures? I've heard of several lately...I've always been more of a Briggs guy

Link to comment
Share on other sites

Greg:

I am not sure I would say that they are prone to rod failures, but if run low on oil that is often the case. I have always thought of the single cylinder Briggs as bulletproof, but I really like the Kohler twins. If cared for, just like any engine, they are great motors. I think the Briggs are more forgiving of abuse.

Link to comment
Share on other sites

I normally agree with Brett's thinking that Briggs are more forgiving

However I had the experience with a Vanguard that makes me wonder

In my case however I believe it was an oil change without putting oil in

As Brett stated if you take care of them properly

They are good engines

Link to comment
Share on other sites

Ron,

I was speaking of the old single cylinder Briggs, they just seem to me to last forever. The newer Vanguards I have no experience with.

But yes if properly serviced, all of them, Kohler, Briggs, whatever, I thinkcan easily make their service life.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...