Blower shear bolt help please!

[jeppy]

New to the forum wow great site!!

I have a Kubota BX2350 with snowblower. Have owned it for 3 years and periodically break a shear bolt and replace, no biggie. The other day broke the impellor shear bolt and the remnant was VERY difficult to remove with a drift particularly given the tight quarters etc. Usually a couple light taps and out it comes. Not this time. Lots of pounding and bad words. There's a visible guide hole on the shaft that aligns the hole properly so no problem there. Using factory speck bolts, as always. Finally got the remnant out but replacing a new bolt offered great resistance and persuation, way in excess of normal. The resistance is in the shaft itself not the sleeve.

Any thoughts on how to ease the friction/resistance to facilitate easier removal and replacement next time around?

Thanks!

 

[oosik]

jeppy - Welcome to TBN and the forum. Unfortunate that your first post is a problem - but that's the way it is.

In my humble opinion(IMHO) - something got "smeared", "stretched", "galled" or the impellor shifted slightly on the shaft, etc etc when that shear bolt sheared. I would find a new, sharp drill bit the exact same diameter as the shear bolt and ream out the hole with the bit in a hand drill.

Tight quarters won't allow this - HuH??? Well, then - get a round rat tailed file and have at the hole. All you are trying to do is smooth things out. File a little and then try the shear bolt to see how it fits. Don't over do it with the file.

Depending upon how much clearance you have - a good sized punch or awl could bring the impellor and shaft back into alignment - if that's what seems to be the problem.

Chances are very likely that the situation is compounded by years of accumulated corrosion and rust also.

 

[George2615]

Welcome to TBN....

Since you are using factory spec bolts and you are finding them hard to install I'd suggest clamping the bolts in a vice and sanding them with some emory or sand cloth first. That may take off just enough to make the bolt go in better. Also use some anti-sieze or fluid film as a lubricant.

 

[msb1766]

Like the ooski said there was something holding the bolt in, next time rotate the shaft 180 degrees so you are not trying to force the burr through the shaft.
This is what I use for anti-seize:
Amazon.com: Permatex 878 Anti-Seize Lubricant with Brush Top Bottle, 8 oz.: Automotive

 

[jeppy]

Thanks George what about the threads won't that ruin them?

 

[jeppy]

jeppy - Welcome to TBN and the forum. Unfortunate that your first post is a problem - but that's the way it is.

In my humble opinion(IMHO) - something got "smeared", "stretched", "galled" or the impellor shifted slightly on the shaft, etc etc when that shear bolt sheared. I would find a new, sharp drill bit the exact same diameter as the shear bolt and ream out the hole with the bit in a hand drill.

Tight quarters won't allow this - HuH??? Well, then - get a round rat tailed file and have at the hole. All you are trying to do is smooth things out. File a little and then try the shear bolt to see how it fits. Don't over do it with the file.

Depending upon how much clearance you have - a good sized punch or awl could bring the impellor and shaft back into alignment - if that's what seems to be the problem.

Chances are very likely that the situation is compounded by years of accumulated corrosion and rust also.

I can borrow a 90 degree drill and use the exact same diameter reamer bit also. Would a chain saw sharpening file work better?

 

[oosik]

I've done what George said and had two results. First time I took to the shear bolt with my bench grinder. Way to aggressive and the threads WOULD NOT accept the nut. No great loss - I drilled a tiny hole on the threaded end of the shear bolt - drove it into place with a rather large hammer and put a nail thru the hole to keep the shear bolt in place.

Next time I used a bastard file and had the nut on the bolt. Move the nut up/down the threads to keep them "clean" and still reduce the overall diameter. Worked like a champ.

 

[oosik]

I'd say a 3/8" or so chain saw file would probably work great. Be careful - a chain saw file is unlikely to "center" itself perfectly in the drill chuck. Go slow.

 

[George2615]

Thanks George what about the threads won't that ruin them?

Clamp the bolt in the vice by the head and only sand the shoulder, not the threads. The threads will already be a smaller diameter due to cutting them.

 

[currierej]

Being in oklahoma I don't have any experence with snowblowers, but my brushhog had a shear bolt.
I replaced it with a clutch, it replaces the shear bolt with a grade 8 bolt and has a slip clutch design that protects all the gears and works, while not requiring replacing anything.
I got mine from agri-supply for about $60