# Craftsman 536.887990 29"/9HP - Replace Impeller Pins with Bolt/Nut?



## Eb3

Greetings all,

UPDATE/NOTE: Further research indicates the pins I'm talking about for the impeller are rolled steel and apparently are not meant to shear. I'd love confirmation of that from someone here if at all possible. If' that is indeed the case, then I shouldn't have an issue replacing the roll pins with bolts/nuts. Of course I'm looking for confirmation on that as well as anyone who may have gone this route or knows any reason to red-flag the idea. Thank you!

Original Post:
Last season my Craftsman lasted 1/2 a pass on my driveway of the first storm before I suffered a double failure and put it away for the season, I was that frustrated with it. First, my impeller pins went so I had to replace those (boy, is THAT a story and a half) but I'm left wondering if I can replace the 1/4 x 1-1/4 pins (p/n STD572512) with a nut and bolt assembly instead. This latter configuration would be SO much easier to replace if they go rather than having to drive old broken pins out and new pins in during the cold and snowy weather. I don't have a heated workspace so doing repairs can be a real bear.

My second failure was just diagnosed yesterday when I finally got over my disgust of the unit and found my auger belt jumped off the pulley. I got a new belt today just in case and look forward to getting that part squared away, at least.

So my questions are these: Has anyone employed a switch in fastener on the impeller from roll pin to bolt/nut and, if so, do these need to be shear strength?

Thanks, in advance, for any input or feedback you have.

Thanks,

- Ed.


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## nwcove

the rollpins failed on my old ariens last winter due to corrosion, and i was tempted to replace them with bolts. but after thinking about it , decided it was a bad idea. those pins are a designed failure point to protect other much more expensive parts of the machine. ( a box of a couple hundred assorted pins cost about 10 bucks ). it is a bit of a pita to replace them, but it is a somewhat rare failure.


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## Eb3

Thanks for the note back. I thought it might be a point of failure to save the gears but then I thought and read if they're rolled steel, how much of a failure point do they provide? More research/feedback needed.

Thanks again.

- Ed.


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## HCBPH

If you're talking about the pins that attach the impeller to the shaft, you can use small bolts temporarily. They are not shear pins like on the auger rakes. You can get a box of them cheap at HF, that's what I did. If you have bolts, the nuts could come off or something snag on them and wrap around the shaft.


A centering punch is a good way to drive out the old ones, done that many times.


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## sidegrinder

If you think about it, there really isn't a lot of torque at the impeller. I think snapping those rolled pins is a freak occurance. I believe they are just there to make manufacture a little easier. There are plenty of Craftsman, Jacobsen, Simplicity, and John Deere machines that have the impeller welded to the shaft. It's just more expensive.


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## nwcove

i agree, not much torque at the impeller.....until that frozen newspaper, stick or perfectly wrong sized rock gets fed in the machine, imho, its at that point when i'd prefer a roll pin to fail rather than the impeller tip speed going from xxxx fps to zero in a fraction of a second.


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## sidegrinder

Yes, if they actually fail. I've seen dozens and dozens of impellers that were bent to ****. Never seen any broken pins...


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## nwcove

and that is an inherent problem with rust, not design . the pins could be non existant and the impeller might as well be arc welded to the shaft due to rust.


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## sidegrinder

As I said earlier, just as many impellers come factory welded to the shaft as come pinned. And as you pointed out, if you don't periodically grease your impeller bore, it might as well be welded anyway. All that being said, I will say that Honda does have a design with an actual shear pin on the impeller that is identical to the ones on the augers.


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## Eb3

Quick update - I went to replace both pins yesterday using a "trick" I saw somewhere on the internet where you bore a hole in the cowling which will allow you to drive the pins out using a long punch. I found one pin was missing completely and the other is rusted to ****. I had zero luck getting the old one out and a new one in the open hole because the impeller wasn't aligned enough to get the pin engaged in the shaft; it was off by just enough to prove it impossible without taking the whole front end off and apart to do it the right way.

Without an actual service manual, I won't try it because my history with this kind of thing proves again and again that I always have parts left over when I reassemble. I'm not afraid to do the work, but I want to do it right and don't want to screw it up. I think it may be time to take this to a professional and just have the whole thing tuned up/adjusted from top to bottom.


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## skutflut

This is where your digital camera is your friend. As you disassemble, take pictures of each part in its proper place, as you disassemble. You will have a visual roadmap of where to put them during reassembly. 

Hate to say it, but some of the manuals out there are as much as useless when it comes to identifying parts and assembly order. The drawings are often bad plus I have found the manuals for some of my equipment just plain WRONG with part numbers.


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