# Snowbird 7040-0 eats a few impeller pins like candy...



## greatwhitebuffalo (Feb 11, 2014)

well we live, we learn...the impeller roll pin fell out on the Snowbird today. dug through the hardware can, and found a stainless 1/4" fine thread bolt, and nylon self locking nut. installed that. 

the machine snapped it off and spit the bolt parts out somewhere....never did find them...

ok you little bugger, dig in the hardware can again, found a HARDENDED ALLEN HEAD bolt, coarse thread 5/16" diameter, and a self locking nut for that. threaded that on. took a few pics to show "it's fixed now"

ran the machine a little more, it promptly SNAPPED THAT OFF TOO. !! 

ok that means war...stopped by the hardware store and bought a hardened 5/16" roll pin, a clevis pin with matching lock pin, and a hardened 5/16" coarse nut self locking. one of these has to work.

figured try the roll pin first being that's what was in there before. from working with them before I know they are very hard and nearly impossible to break, to shorten them you have to grind them down.
this roll pin is a lot longer than oem so hopefully it will grab some material on the side too. it should stay put. tapped that in and hopefully it won't shear that off ??

good fun...but I'm just wondering, why alluvasudden is it breaking these ?


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## classiccat (Mar 1, 2014)

I think it's because your engine is on backwards 










I'm not familiar with the breakdown of that impeller; is there slop in the bushing/bearing allowing the impeller to smack off of the housing somewhere?


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## greatwhitebuffalo (Feb 11, 2014)

no play there, but I think the problem is, there is slop in the roll pin holes both sides, on the impeller, from age and wear. there's a slight amount of slop on the roll pin hole in the shaft itself. a few thou when inserting a 5/16" bolt. it should be tight and not wiggle at all.
the impeller bangs around against the roll pin. or whatever is put in there as a pin. that gives it a head start enough to break them off.

the new roll pin was already bent, and starting to fall out and all I did was run the machine in place, didn't even blow any snow with it yet.

the roll pin the previous owner had in there, was also loose when I got it, but he has a small screw with nut and washers on each side of the roll pin, through middle of roll pin- so as it moved back/forth it would be caught and held in place by the washers.

I may have to do that to get it to stay there. or find a very strong hitch pin like the hardened type used on trailer towing hitches, that won't snap off.

in the meantime I removed the new roll pin, coated it with super glue gel adhesive, and drove it back in there.

if you ever want really strong "locktite" that stuff is it. I've put it on threads before, and when disassembled years later, it take heat from a torch to get it to release. otherwise it will rip the threads off the bolt as it's unthreaded. one time a bolt snapped in half before it released. that's just how strong it is on threads.


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## motorhead64 (Dec 15, 2013)

Can you drill both to a larger size for a larger pin? MH


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## greatwhitebuffalo (Feb 11, 2014)

I could drill it to 3/8" pin size. but that would start to make the drive shaft thinner. if that shaft breaks the machine is a dead player.

the insane part is, it broke off a hardened allen bolt/nut, and a stainless bolt/nut. holy cripes !!

if it drops the roll pin, I'm going to try a grade 8 bolt.


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## motorhead64 (Dec 15, 2013)

Another option may be to fill both holes with weld, then re drill to spec. MH


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## Kiss4aFrog (Nov 3, 2013)

Welding and drilling sounds like the best bet.


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## ELaw (Feb 4, 2015)

Agreed... although the holes must be drilled in *exactly* the right place.

Or... assuming there's one pin, or two with one in front of the other... how about drilling new holes in the impeller 90 degrees away from the existing ones?


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## micah68kj (Oct 8, 2011)

Just drill new holes in the original size, a little way from the old holes. You keep putting bigger, hardened bolts in there and soon you won't have to worry about them breaking. You'll be looking for a new set of gears.


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## Blue Hill (Mar 31, 2013)

micah68kj said:


> Just drill new holes in the original size, a little way from the old holes. You keep putting bigger, hardened bolts in there and soon you won't have to worry about them breaking. You'll be looking for a new set of gears.


+1 If I kept snapping bolts, especially hardened bolts, I would ask my self why. IMHO, instead of putting in bigger and stronger bolts and pins I would be trying to find the root cause. Shear pins are the weakest link for a reason. They are meant to be sacrificial to fail before something more major (and expensive) gets damaged. Just sayin'


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## Sid (Jan 31, 2014)

Can you turn the impeller shaft fairly easily? Is there enough grease, or oil in the gear box?
There"s something else going on I think. I agree that drilling the holes out to 3/8" would work with out doing much harm.
Sid


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## Sid (Jan 31, 2014)

I just rebooked at the picture, and I see that there is no gearbox on that unit. So I think that is probably the impeller shaft bearings, or something binding in that shaft.
Sid


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## nt40lanman (Dec 31, 2012)

Roll pins are hardened spring steel. Stainless bolts are mushy by comparison. Even regular bolts are not as tough in the right application. 

Does it have 1 or 2 roll pins? My Ariens has 2.


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## greatwhitebuffalo (Feb 11, 2014)

Sid said:


> Can you turn the impeller shaft fairly easily? Is there enough grease, or oil in the gear box?
> There"s something else going on I think. I agree that drilling the holes out to 3/8" would work with out doing much harm.
> Sid



when the machine is off, and in neutral, the impeller spins effortlessly by hand

it broke this hardened allen and self locking nut like it was a piece of straw, there was nothing even left in the hole after it broke. this pic taken after I first installed the allen


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## greatwhitebuffalo (Feb 11, 2014)

it also broke off a STAINLESS 1/4" bolt with locking nut, before it broke the allen bolt. now I have a roll in there locked in place with super glue gel. it's holding up so far, I used the machine to clear down to the shed and back.

if that falls out or breaks, I'm going to try this stuff

a clevis pin and grade 8 bolt w/self locking nut


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## greatwhitebuffalo (Feb 11, 2014)

nt40lanman said:


> Roll pins are hardened spring steel. Stainless bolts are mushy by comparison. Even regular bolts are not as tough in the right application.
> 
> Does it have 1 or 2 roll pins? My Ariens has 2.



true...but it also BENT the roll pin that's in there now.

grade 8 bolts are what holds your car together, and holds the crankshaft in the bottom the engine, and the connecting rod caps on the engine, at 6000 rpm under load making 400HP on a big V8

we're not talking weak stuff here, even if it is grade 8.

it's also what holds the flywheel and clutch on the engine, when it's revved to 6000 rpm and the clutch let go. 

and grade 8 is also what holds the ring gear on the differential in a car, and takes all the power the engine can make at wide open

and they hold the wheels on the hubs on a car too

grade 8 is STRONG- they don't just sheer off like that. I haven't tried one yet. I don't know if the allen bolt is harder or softer than the grade 8.


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## greatwhitebuffalo (Feb 11, 2014)

Sid said:


> I just rebooked at the picture, and I see that there is no gearbox on that unit. So I think that is probably the impeller shaft bearings, or something binding in that shaft.
> Sid



nothing is binding. you can spin it with one finger.

I believe it's simply play in the impeller to shaft, lets the impeller rattle around on the shaft instead of staying tight on there. that allows it to bang on the pin whatever it is, allen, grade, 8, roll pin, etc. until it snaps it.

the shaft is hardened steel and not really worn, a tiny bit if any at all. but he impeller hole is starting to elongate noticeably. it was like that since day 1 when I bought it. just recently it started dropping the pins.


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## greatwhitebuffalo (Feb 11, 2014)

Kiss4aFrog said:


> Welding and drilling sounds like the best bet.


 
THAT'S what I was thinking...weld a 5/16" hole size steel washer on each side of the impeller hole, where it's worn oblong- then install a new roll pin


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## Sid (Jan 31, 2014)

Yeah, any play in the holes in the auger tube will work on anything in that hole. I agree with another poster that a second hole [and pin] will probably fix it.
Sid 

On a second look at that impeller, it looks like light duty.
Sid


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## CarlB (Jan 2, 2011)

I would drill another hole in the impeller at 90 degrees to the original. If you are worried about the extra holes just weld up the original ones.


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## greatwhitebuffalo (Feb 11, 2014)

*when in doubt, check manual*

I just downloaded the manual for this Snowbird machine
it shows right in the exploded diagram of the machine, that a 5/16" bolt goes through the middle of the roll pin in the impeller, with a washer on both sides, to hold it from slipping out, and a nut on one side.

so that's what's "posta" be there !


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## greatwhitebuffalo (Feb 11, 2014)

CarlB said:


> I would drill another hole in the impeller at 90 degrees to the original. If you are worried about the extra holes just weld up the original ones.


excellent idea...that will be a warm weather spring project.
just so the weld doesn't get down inside the shaft hole
in the meantime, I checked the manual, there's supposed to be a nut/bolt and 2 washers through the middle of the roll pin, shown right in the owners manual

cleared the driveway with the machine this morn, and just when I got done, it broke the shorter rear drive belt, the outer belt. the inner (reverse drive) belt is quite frayed but still works. I'm going to buy 2 new belts for the machine. 

anyone know the size ? the number on the inner belt is M1062360 and it measures at 1/2" x 36"
does that sound right ?


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## greatwhitebuffalo (Feb 11, 2014)

Sid said:


> Yeah, any play in the holes in the auger tube will work on anything in that hole. I agree with another poster that a second hole [and pin] will probably fix it.
> Sid
> 
> On a second look at that impeller, it looks like light duty.
> Sid


yes I agree, the impeller looks tinny. but it's hardened sheet steel. that impeller is TOUGH. 
this little machine really throws the snow, with much more authority and force than the Gilson Unitrol with the bigger 8HP Briggs, and the Snowbird is only 5 HP. 

I think it's because the impeller is separate from the augers and is spinning much faster than it would be, if it was part of the auger drive. that sucka is really moving in there. the ratio for the impeller must be cranked up a bit, faster than atypical machines with auger/impeller on same pulley/shaft. 
someone mentioned in another thread, that the impeller speed must be modest on a machine where the impeller also drives the augers, and that seems to make sense. with it separated like this, enables spinning that impeller at a higher speed and get more throwing distance.


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## greatwhitebuffalo (Feb 11, 2014)

I found the belt sizes. the reverse belt is a 1/2" x 40" 

the forward drive belt, is an oddball- taking the number off the owners manual, that is a 1/2" x 35.4"

not a true 36" belt

looked around here, and found a used but good condition 1/2" x 35" that came in on a Gilson 55012, and was too short for the Gilson- it would keep the augers engaged at all times.

put it on the Snowbird, re-adjusted the idler, she's a runnin' agin'.

actually engages much better too, with the shorter belt.


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