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Discussion Starter · #1 · (Edited)
The following video and description below it (when you open it in Youtube) pretty much sum up what I've been going through the past few days.
In short, I'm not a happy camper.

After making the video I removed the connecting rod and piston and then removed the pin that secures the top of the connecting rod to the piston, freeing the pistion, pin and connecting rod.

In short, the pin fits nice and sungly into both sides of the piston, but the connecting-rod-to-pin is pretty sloppy, IMO. The connecting rod piston-end looks fine. The piston pin, however, has a, how to put it, depression where the connecting rod grips onto it. When the connecting rod is surrounding the pin, it is possible to very slightly tilt the connecting rod on the pin, without the pin moving at all. Just another indication of not a snug fit.

If you agree that the above video shows unacceptable sloppiness, what parts should I replace -- the connecting rod and pin, or should I go beyond that to the pistion and crankshaft?

Just exactly how tightly should the connecting rod grip the piston pin?

Thanks for any advice.
 

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Off hand I'd say the rod, but how are the bearings? The pin description does not sound good either, is anything installed new? The piston and crank pin for the rod should both be a snug fit but yet rotate freely, make sense?
 

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Discussion Starter · #3 ·
Off hand I'd say the rod, but how are the bearings? The pin description does not sound good either, is anything installed new? The piston and crank pin for the rod should both be a snug fit but yet rotate freely, make sense?
Yes, that makes perfect sense. If you watch the vidoe on Youtube's site, here's what I wrote for a description.

I bought a Toro Power Clear 821 QZE on Nov. 6, 2020 and used it for the 2020-2021 winter season. On August 3, 2021 (after having had the leaking crankcase cover gasket replaced under warranty), I pushed the blower into the garage, parked it, and there it stayed until Nov. 8, 2021 (two days after the one-year warranty ran out), when I checked the oil level, ran it for a couple of minutes and then changed the oil. It ran for a bit after chaning the oil, but then this noise started. The noise sounded to me as if something was rattling around in the crankcase. Because the warranty had expired, because I am retired, I decided to do some diagnosis of the noise problem. Before doing anything, I removed the spark plug and ingnition key and pulled the recoil starter. A knocking noise was instantly apparent. I removed and disassembled most of the engine. I removed the head and valve train components including cam, lifters and push rods. To narrow down the engine noise I re-installed the crankshaft, piston+connecting rod and connecting rod cap. But before I put the crankcase cover in place I decided to turn the crankshaft back and forth a bit. IMO, either the piston, the connecting rod or the connecting rod's piston pin are waay too loose.

So there you have it. This was a new machine November 2020. Now I have to deal with this problem without any warranty help.

There are no separate bearings on either the steel-crank-end of the connectng rod or the steel piston pin end -- in other words, just the aluminum connecting rod's bearing surface rubbing against the steel bearing surface of the crankshaft and the steel bearing surface of the piston pin. I'm thinking that the opening on the connecting rod that the piston pin goes through has worn slightly elongated top to bottum, but I can't prove it because I do not have an inside micrometer to take measurements.

But I do have an outside micrometer that measures to the ten-thousandth of an inch, so I measured the OD of the piston pin where the connecting rod usually rests and rotates a bit, as well as the OD of pin where it is held into position by the two bottom ends of the piston. The OD of the former is 0.7065" and the latter is 0.7083", so there is at least 0.0018" of space between the rod and the pin. This space would be regarded by many sources I found as being too much. When the pin first passes into the conneting rod, the larger portion of the pin fits that opening more appropriately than the area of the pin where it normally operates. You can hear for yourself how the piston pin "slaps" inside the connecting rod when the connecting rod changes direction. The connecting rod still fits snugly on the crankshaft, with no discernable play, although there has to be at least some space between any two bearing surfaces.

The piston pin fits nicely into the piston. The fact that the piston-end of the connecting rod is relatively small compared to the crank-end is IMO the reason for its accelerated wear. Too bad Toro did not use separate bearings at least at that one wear-prone location.

I've got to decide which parts to buy, pronto, because winter could arrive literally tomorrow here in Edmonton, Alberta. After measuring with the mic, I think I will first order a new connecting rod and piston pin and, before installing in our machine's engine, see how snugly the new pin fits in the new connecting rod.

After having had this experience, I'm thinking that this engine is not designed for longevity, although it is possible that I just happened to buy a machine with a softer than normal connecting rod. I'd hate to think that I would have to go through this after every winter in the future.

I hope other owners of this model will chime in with their experiences -- good or bad.
 

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In my experience I dont recall ever seeing a piston pin sold separately? Can you take just the motor alone to a Toro dealer and show/explain your findings to them? A decent and experienced shop should/will look after you considering the purchase date and time alasped. (I thought Toro's came with a 2 year warranty?)
If they wont, then order what you need.

have to go through this after every winter in the future
No, you have a very rare problem.
 

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Discussion Starter · #6 ·
In my experience I dont recall ever seeing a piston pin sold separately? Can you take just the motor alone to a Toro dealer and show/explain your findings to them? A decent and experienced shop should/will look after you considering the purchase date and time alasped. (I thought Toro's came with a 2 year warranty?)
If they wont, then order what you need.



No, you have a very rare problem.
After hearing the noise after changing the oil, I took the machine to a local Toro dealer to have some experienced person with these machine have a listen during running and simply tell me if that sound was normal. I was told that the sound was not normal and that the machine would have to be left there so that whatever was causing the noise could be fixed. I asked if the machine would still be under warranty two or three days after the one- year warranty expired. I was told that Toro was strict about warranty dates and, therefore, to expect that I would be footing the bill. I told the rep. that that because I was retired, I would pay myself the labor cost to fix whatever was the problem, which is what I'm attempting to do.

All of the parts making up this engine, including the crankshaft, connecting rod assembly, piston pin and piston are at least listed separately in Toro's online parts catalog. Whether these can actually be purchased this way I am about to find out. ( Frankly, at this point I would not be surprised to find out the the one and only internal engine part I can buy for this engine is the "engine assembly".:))

BTW, this is not my first "rare" problem with this machine.

First, in early this summer I took the machine to a Toro dealer to have an oil leak fised. Supposedly the crankcase cover gasket was replaced under warranty. I say supposedly because when I separated the cover from the cankcase two days ago, the gasket broke up as if it had been there from when the engine was first put together. Therefore, I suspect that to stop the leak the cover bolts were just tightened ............ which is fine because that stopped the oil from leaking. But the invoice stated that the gasket was replaced, with all that entails, so you draw your own conclusions.

Second, during last winter, not very long after I bought the machine, during cold weather the chute-direction "system" froze into one position. I wrote at length about it and the fix in this forum.

FWIW, I started a thread over a year ago, before deciding which Toro model to buy and continuing it after making my decision, with some nice photos of the new blower sitting next to the Craftsman 12-hp monster which I've mainted for over 23 years (no freezing or engine problems with Old Faithful).

Stay tuned. No doubt I will have much more to add.

Again, I appreciate any and all advice in this latest issue.
 

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I don't know if Canada is different, but in the US my 821 QZE has a 2 year warranty unless used commercially.

I am surely hoping yours is a very isolated issue in spite of that.

I am definitely watching this with interest though.
 

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connecting rod assembly, piston pin and piston are at least listed separately in Toro's online parts
I took a look, sure enough you can, I'm shocked, but I learned something today anyway. Order them up and hopefully all will be well for you, I presume you'll grab a new crank case gasket also.

As a side note, your Toro dealer doesnt come off sounding very accomodating to its customer base, were it me, I'd contact Toro direct and explain your situation.
 
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Discussion Starter · #11 ·
As much as I hate to say it, I have just found out that you folks who told me about a 2-year warranty may very well have been correct. The Toro dealer I took the machine to in order to have the oil leak fixed under warranty was not the Toro dealer from which I purchased the machine, so maybe the former did not have the proper warranty information on our machine and, therefore, did not inform me right off the bat that the machine was still under warranty. If I had left the machine there, maybe they would have investigated the true warranty situation further and informed me of that. But rather than accept the possibility that I would have to pay for labor that I am able to do myself, I took the machine back home to do the repair myself. (Is it possible to kick oneself in the ass?) I have to look upon this as a learning experience. I know a lot more about my machine than I did a week ago.

Regardless of my stupid error, now I have to fix the machine, so I'll just forge ahead on that journey. I've sent out requests for quotes for the piston pin, crankcase cover gasket, valve cover gasket, connecting rod assembly and (that ridiculous) push nut. Because it's Remembrance Day here in Canada, most businesses are closed for the long weekend, so I don't expect to get any quotes before Monday or Tuesday.

Everybody have a nice weekend.
 

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Discussion Starter · #12 ·
Upon closer examination by my fantastic neighbor, who is a power engineer, we have determined that not only is the larger opening in the connecting rod out of round, but the steel bearing surface of the crankshaft is also significanly out of round. In one direction the crank is 1.17795" OD, and in an almost perpendicular derection (the direction of compression and ignition impact) it is 1.17165" OD. The latter subtracted from the former is 0.00629", which my neighbor feels is unacceptable and, unfortunately, I have to agree with him. We now believe that most of the noise in the video originates at the crank/rod interface, but some also at the rod/pin interface.

My neighbor and I cannot figure out how a relatively soft aluminum rod could have worn a hard, round steel crank journal into an elipse in such a short period of running time

About the number of hours the engine has run. WIth the Toro I am able to blow snow off our driveway and sidewalk in approximately 7 minutes. The absolute maximum number of times I blew snow last winter was 30 times, and that is probably a gross over-exageration. When I did my low-temperature test of the machine at well below -30C, I operated the machine continuously for maybe 40 minutes. Therefore, the total amount of time that the engine ran last winter was 40 + (30 x 7) = 250 minutes, which equals 4 hours and 10 minutes.

About oil. As the owner's manual recommends, at around 2 hours of operation I changed the original oil. When the dealership supposedly replaced the crankcase gasket in early summer, they either replaced the oil or captured and re-used the oil that was in there.

When I ran the engine several days ago for a couple of minutes to warm it up prior to changing the oil (the engine ran unattended, I might add), the oil that came out looked well used, even though it had been used for an absolute maximum of 2 hours and 10 minutes. (This is probably normal for 2-hour-used oil, but not for new oil that had maybe 10 minutes on it to run out the last few drops of gas in the tank prior to storage for a couple of months.) Then I replaced that oil with new 5W 30 Quaker State. Then I ran the engine and, after a couple of minutes, I noticed what I thought was abnormal sound; arranged with the dealership to have a listen, etc. as I already described at length above.

BTW, I received two quotes for parts this morning. The lower of the two was just under $90, which isn't so bad. But now I feel that I should also replace the crank, which by itself is going to be close to $140 or even more, so I'm looking at a minimum of $230.

Therefore, now I'm going to reach out to the dealership who listened to the engine (and for some reason did not tell me that my unit probably had one year left on a 2-year warrantly) and possibly also Toro customer support with all this information and see what they have to say.

Alghough I can easily prove how long I've owned the machine, of course I cannot prove to anyone that the machine has been run for under 5 hours, total, because, with the amount of wear on the crank and rod, I have difficutly believing it myself. Is the dealership going to believe me? To answer that question, I'm going to bring to the dealership the crankshaft/connecting rod/piston assembly and hand it to the rep., tell my story about the total number of hours on the unit and listen to what they have to say.

If I don't hear what I'd like hear at the dealership, I will write to Toro customer support somewhere and tell them the same story.

Any advice on what I should say and how I should say it to both?

While I'm typing, how many hours of run-time do you think that it would normally take to produce the wear that is on my crank and rod (somehow that didn't sound right)?

My goal in doing this is to get either free parts or discounted parts for a machine I bought one year and six days ago. Repeat: One year and six days ago. Is that too much to ask?

Thanks.
 

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Discussion Starter · #13 · (Edited)
I should have added to my last comment that the larger rod opening ID at its bearing surface is 1.224409". The smaller of the two crank OD readings is 1.171653". The latter OD subtracted from the former ID is 0.052756", rounded to significant figure 0.0528", which, again, is a completely unacceptable amount of "play".

I have been completely stumped on what has caused the excessive wear on an egine that has had so little run time, but being a very suspicious SOB, a theory has popped into my little brain today. Tell me honestly what you think of it.

When I went to the Toro dealer from whom I bought the unit (again, in early Nov., 2020), I thought that I would be taking home a unit in an never-opened box. When I mentioned this to the sales person, he told me that they had some units that had already been assembled "in preparation for the upcoming increase in sales", so I would not have to do all that assembly and have a box to dispose of.

I found that reasoning logical and acceptable, but now that my unit has had this mysterious, inexplicable problem of excessive wear, I can not help but wonder if I was sold a "demo" unit or, even worse, a loaner unit that was loaned out to whoever left a unit at the dealership for service. Of course doing that would be unethical and possibly illegal, but so what? Who is going to notice the fraud? just roll the dice and if you just happen to have the unit come in for repair during the warranty, fix it under warranty and get paid by Toro for doing the job. Everybody's happy. If the unit comes in for repair after the warranty expires, too bad for the owner of the machine and, hey, if you play your cards right, maybe you can sell him another "better" blower.

This is the one and only logical explanation that I can think of for the excessive wear ............ not only on the aluminum rod, but also on the steel crank.

My theory, simply put, is that the unit has vastly more hours on it than I think it has.

Can you think of any other reason for the excessive wear?

BTW, yesterday I cleaned the carb on our 24-year-old 12hp Craftsman monster-blower and it's now running great, ready for action. So I'm no worse off now that I was before buying the Toro (whose parts are now sitting on a bench in the garage). So, let it snow, let it snow, let it snow!
 

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I feel your pain for the situation you find yourself in.

If the unit had been lent out as a loaner or had many hours of use on it, it would be fairly easy to notice compared to a new, never used machine.
 

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Discussion Starter · #15 ·
I feel your pain for the situation you find yourself in.

If the unit had been lent out as a loaner or had many hours of use on it, it would be fairly easy to notice compared to a new, never used machine.
You may very well be right, although cosmetically, our unit still looks like new. Even the paddles still look excellent ( but I understand that it's a quick and easy procedure to replace paddles). There was a notceable scratch on the shroud when I bought it, but I thought is was not worth complaining about.

Frankly, I have no idea what a high-hour unit would look like cosmetically, but if the situation with snowblower ownership is anything like automobile ownership, cars with equal miles on the odometer can look vastly different cosmetically. It all depends on the fastidiousness of their owners. For example, if I borrowed a blower from a dealer or a neighbor, I'd take extra special care to return it in the same condition it was in when I borrowed it.

I'm just grasping at straws here. Again, you may very well be right about it being pristine new when I bought it. But then I'm left with trying to figure out how all the wear occurred. If the wear was just on the rod, I might logically argue that the aluminum rod was faulty. But the fact that the crank was also worn out of round means that both the crank and the rod were defective, which would be too much of a stretch of logic.
 

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I would get hold of Toro customer service first (Tech. Dept.) , have all your info carefully wrote down from start to finish and see where it goes.
How you present this to Toro will be very important and hopefully you get a person who agrees with your situation . An engine should never have wear like that after light use and an examination can soon tell if the metal used is at fault . Toro actually should take some interest in this as there may be other cases like this as well and may come down to a bad batch.
 

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I should add that there was likely a clearance issue when that engine (and the one in the video) were manufactured . The noise would not be very noticable at first and to the untrained ear not detected till it was really loud . When you get excessive clearance in pin to conn rod and the like the hammering motion will cause wear very quickly.

If it were me calling the shot in the Tech. Dept. you would be getting a new engine installed by the dealer at the very least.
 

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Discussion Starter · #18 · (Edited)
I would get hold of Toro customer service first (Tech. Dept.) , have all your info carefully wrote down from start to finish and see where it goes.
How you present this to Toro will be very important and hopefully you get a person who agrees with your situation . An engine should never have wear like that after light use and an examination can soon tell if the metal used is at fault . Toro actually should take some interest in this as there may be other cases like this as well and may come down to a bad batch.
I should add that there was likely a clearance issue when that engine (and the one in the video) were manufactured . The noise would not be very noticable at first and to the untrained ear not detected till it was really loud . When you get excessive clearance in pin to conn rod and the like the hammering motion will cause wear very quickly.

If it were me calling the shot in the Tech. Dept. you would be getting a new engine installed by the dealer at the very least.
Thanks very much for your input and advice. I really appreciate it. I agree with everything you've said, especially your last sentence!:)

If I understand the theory of lubrication correctly, during operation there is supposed to be a thin layer of oil between the bearing surfaces of the crank, rod and pin. The space between the crank and rod, and rod and pin, is supposed to be small enough to hold the oil and have the oil cushion the blows of combustion chamber ignition, lubricate during crank rotation, and minimize wear if metal parts happen touch each other. Larger spaces allow metal parts to touch and wear each other too frequently. Space beyond a certain point causes a vicious cycle of wear leading to complete failure of one part (usually the rod) and then the entire block. In theory, the metal parts should never actually touch each other, or, if they do, only infrequently. At least I have caught this problem before the engine is a total loss. Right now I'm looking at a repair that is going to cost approximately 1/3 the cost of a new engine.

Your last comment caused me to remember something I noticed during engine disassembly -- the way the cylincer head valve area looked when I removed it. Below is a photo that I took of the head about 20 minutes ago. Do you think that what you see looks like a head that that has been on an engine with less than 5 running hours on it? I have no idea because I don't have enough experience in this area.
Thanks again.
Automotive tire Bicycle part Rim Gas Motor vehicle
 

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You have very tight clearance at the conn rod/piston pin , if machined and fit right maybe a .001-2" at most . Enough so to let oil in to lube but no movement to cause wear from extreme pressure , an engine in reality is trying to self destruct and will if these specs are not met and remain for the duration of time the engine is designed to last.
The stuff at the exhaust valve could be from oil working it's way up the cyl , it does look a bit excessive and may have been cause by the issue....hard call.

Keep us posted when you hear from Toro , don't bother with the dealer right now , the fact that mechanic said that noise was normal tells me the level of knowledge in that shop.
 

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Discussion Starter · #20 · (Edited)
You have very tight clearance at the conn rod/piston pin , if machined and fit right maybe a .001-2" at most . Enough so to let oil in to lube but no movement to cause wear from extreme pressure , an engine in reality is trying to self destruct and will if these specs are not met and remain for the duration of time the engine is designed to last.
The stuff at the exhaust valve could be from oil working it's way up the cyl , it does look a bit excessive and may have been cause by the issue....hard call.

Keep us posted when you hear from Toro , don't bother with the dealer right now , the fact that mechanic said that noise was normal tells me the level of knowledge in that shop.
Thanks again for the input. But I must make one correction to what you said. The mechanic said that the noise was NOT normal. I thought that the noise was not normal, but I was not certain, which is why I brought it to the dealer to listen to. He confirmed my suspicion. But I still think that you may be right about whom in Toro to contact first. To a certain degree the dealership that listened to the sound, told me that it was an abnormal sound, yet did not inform me that the unit had a 2-year warrantly rather than just let me say that "the one-year warranty has just expired" and not correct my mistake and let me walk out of there with my machine knowing that I was mistken, is not exactly a perfectly objective party in the matter. So maybe it is better that I start at the top and work my way down the food chain rather than the opposite.

The other thing I want to tell you is that the video in my first comment is in fact my engine. My gloved right hand is turning the crank while my left hand is trying to hold the camera steady.

When I tried to decide for myself about whether the head looked normal, I first imagined what a new head looks like. Then I imagined starting the engine and letting it sit on the ground running for five hours, then removing the head after only five hours of running. What would it look like? I find it hard to believe that it would look like that photo, but, again, I am not experienced enough to make a judgement. Maybe it looks normal.

Thanks again.
 
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