Forums Archive Index > Outdoor Power Equipment > craftsman snowblower keeps breaking wheel bolt
Date: 25 Nov 2005 12:24 pm
Would anyone have any ideas why our snowblower keeps breaking the wheel bolt. Its a 12 hr craftsman snowblower. It seems like since we replaced the
"hex shaft", the bolts on the right wheel keep breaking when working hard. Is this just a coincidence or would it have something to do with it, maybe something is not lined up inside. We replaced the bolt and the machine drivers well, but then the bolt snaps off.
Any ideas?
Date: 25 Nov 2005 12:29 pm
Just some thoughts from my shade tree mechanic experience.....
Is it a nice snug fit for the bolts and the holes they go through?
Are the holes ovaled out?
When the parts were replaced, were these bolts replaced with "new" ones?
Proper torque?
Proper grade bolts?
IF someone replaced the bolts, and decided to "upgrade", in many cases a grade eight is not the best choice as some might think. The proper grade is needed for the type of loading it will see.
Date: 25 Nov 2005 12:36 pm
The shaft on the wheel itself is oval but not on the axle, could that be the problem? If thats the problem how could I fix it without buying a new wheel? The owners manual says the replacement bolt is a 1/4 X 1-1/2 bolt
GR 5. Thats what I was using. I dont know the torque, my husband just tightened it has much as possible. Thanks for your ideas.
Date: 25 Nov 2005 12:45 pm
I don't think the hole should be oval.
Do both side keep breaking bolts?
If not, is the other side oveled out?
I would guess not, would be my bet.
I think that would be the problem, the wheel is slamming into the bolt and cutting it. Grade 5 sounds right, it's softer than a grade 8, and better for that application from what I know.
The torque spec is low,
only about 8 ft/lbs.
To tight isn't good either.
torque spec table
Date: 25 Nov 2005 12:57 pm
just the right wheel is oval, i just took a look at it and you can definately see that it has been worn to a oval shape. The other wheel is perfectly round and it has the "click pin" holding it on. What if I used the click pin on the right wheel, would it be stronger than the bolt, or what if I went to a stronger grade bolt? Its just the right wheel that snaps the bolts. I guess its pretty hard to impossible to make a oval hole round again, Ha Ha.
Any ideas?
Date: 25 Nov 2005 1:07 pm
wendyk wrote:
just the right wheel is oval, i just took a look at it and you can definately see that it has been worn to a oval shape. The other wheel is perfectly round and it has the "click pin" holding it on. What if I used the click pin on the right wheel, would it be stronger than the bolt, or what if I went to a stronger grade bolt? Its just the right wheel that snaps the bolts. I guess its pretty hard to impossible to make a oval hole round again, Ha Ha.
Any ideas?
The click pin is probably softer and will start to bend from the beating of the wheel rotating on the shaft, and start to get dent's in it and finally break.
There are a few ways to make the hole round again.
One is to drill it out.
But I would fear that the new hole size would be too big for the saft and the saft would be wasted. Also one could weld shut the hole and redrill or weld a sleeve into the wheel. But I suggest that the easiest and best thing todo it get a new wheel. Is the blower old? maybe it's time for new tires or the rims were rusting? ( just more reasons to justify new rims/tires)... My 5/25 sears rims were rusting by the bead and not holding air for more then a month.
Date: 25 Nov 2005 1:12 pm
we bought the machine new in 1988 and have maintained it ever since, we store it inside so its not rusted. I really like your idea of welding a sleeve or even welding it shut and redrilling. My brother is a Welding Hobbiest and I could get him to do it. Thanks alot for the idea, I never thought of that.
Thanks again
Date: 25 Nov 2005 1:23 pm
Welcome to the forum wendyk. I'm trying to picture it in my mind, but my mind is all ready set on Saturday. I'm sure that you will get lots of suggestions from the guys.
Sherri
Date: 25 Nov 2005 1:32 pm
Hi Sherri, it's the hole that's in the wheel, a bolt goes through the hole and ties the wheel to the drive axle.
Other machines have those click pins, to open up the axle to make it easier to move around when off.
Wendy, my old sears was bought in about 1989, I too kept it stored well and in a nice clean shed. But after soo many years of exposure the the salt in the end of the driveway.. the bead area of the rims where the salt got jammed into, has surface rust that made it under the bead of the tire and one leaked air. If it were my blower, with the condition of my rim/wheel. I would replace it. If your's are in perfect shape, try the sleeve. if you drill out the wheel, insert the sleeve, bolt it onto the axle, then tac weld, remove the wheel from the wheel finishing the welding, you wont' have the problem of trying to line up the new hole when drilling the welding filler.
Date: 25 Nov 2005 1:36 pm
Im going to get a price on a new rim, its a great machine. I dont mind spending the money on a new rim, it cheaper than buying a new one.
thanks for all your help
Date: 25 Nov 2005 3:26 pm
Another suggestion is to remove the rim/tire. Then drill a NEW hole approxamately 90 degrees from the old one. Use the good wheel to size it up & see what size hole is required. Should be an easy job...
Marty
Date: 25 Nov 2005 4:32 pm
Thanks for your idea, I think I will try it.
Date: 25 Nov 2005 5:23 pm
ill save you ...no problem
the original bolt was a bit different than the new ones you have been getting.
it was indeed 1 1/2 inches long by 1/4 and grade 5...
however if you had the pieces of it you would notice right away that it only has about 5 threads on it.just enough to secure the nut.
your new bolt has threads at least half of its length,these extra threads make it very weak in the threads and this is where it will break on you.
so you must get a bolt that is 2 1/2 inches long,this will allow all the threads to protrude through the wheel resulting in your wheel staying put.
chris
Date: 25 Nov 2005 5:39 pm
Good one..
I didn't think of that, they have a real long shoulder...?
The oveling of the hole doesn't help, but even after taking care of the bolt it still might break, right? Just might last longer?
If they invest in a new wheel, they must use the right bolt or they'll be back at square one shortly.
-Bob