Shear Bolt vs Regular Bolt

[Oldoak]

Remember to properly maintain those slip clutches. The manual for my Land Pride rototiller calls for the tension screw on the slip cutch to be backed off at the start of every season and allow the clutch plates to slip, then reset the tension screws.

When sitting idle for months at a time the clutch plates can cease together acting like a solid shaft just like some people reporting the main clutch on their tractor not releasing when depressing the clutch pedal after not being run for a long time.

 

[newbury]

On my snowblower there are 2 shear bolts for the auger and 1 for the fan. The shear bolts cost around $6 each, and I am always going thru them. I use the grade 2 bolts (which the original shear bolts were) and use my lathe to make the grooves in them. You could also make the grooves in them by chucking the bolt into a drill and then hold a file to the bolt areas that you want the grooves to be. (A dremel works even better to make the grooves). I make up 20 of them in the beginning of the snow season and they cost a few cents each vs $6. BTW I always add 2 to the number of hash marks on a bolt to get the grade. 3 hash marks on the bolt head is a grade 5, 0 hash marks on the head is a grade 2. I find that if you don't make the groves in the bolts they are harder to drive out of the shaft after they shear,/w3tcompact/icons/sad.gif if you do have the grooves they just pop right out !!/w3tcompact/icons/smile.gif Hope this helps.

Since Jason has not been around since '05 does anyone else put grooves in their shear bolts?

Old thread I know, but I've got a Bush Hog Rhino that snaps those ungraded TSC 1/2 bolts like they were pretzels. Sometimes just a clump of grass will shear them and if the blade hits nearly anything they snap. I've been tempted to use grade 5 where a know its a pretty clean mow but, since I've got the bolt changing down to a science, I'm faster than the dad on "A Christmas Story" changing spare tires.
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But good thread - I had not read before about grooved shear bolts.

I have no problems with the non graded bolts I but from HD, Lowes, etc

I do, they are expensive compared to TSC. I think I paid $1.89/lb for a bag full a few years ago.

 

[kenmac]

I do, they are expensive compared to TSC. I think I paid $1.89/lb for a bag full a few years ago.

I usually don't hit things that break that cause the bolt to break.
I haven't broken one in yrs. I keep about 3-4 on hand just in case.

If I were break bolts every time I used the cutter. I would mark the bad areas. Or buy a plenty of bolts to keep on hand

 

[pmsmechanic]

Remember to properly maintain those slip clutches. The manual for my Land Pride rototiller calls for the tension screw on the slip cutch to be backed off at the start of every season and allow the clutch plates to slip, then reset the tension screws.

When sitting idle for months at a time the clutch plates can cease together acting like a solid shaft just like some people reporting the main clutch on their tractor not releasing when depressing the clutch pedal after not being run for a long time.

I repaired a mower where the owner didn't do the above. It was an expensive repair.

 

[MF283]

Old thread I know, but I've got a Bush Hog Rhino that snaps those ungraded TSC 1/2 bolts like they were pretzels. Sometimes just a clump of grass will shear them and if the blade hits nearly anything they snap. I've been tempted to use grade 5 where a know its a pretty clean mow but, since I've got the bolt changing down to a science, I'm faster than the dad on "A Christmas Story" changing spare tires.

I was reading another post and it said that the problem might be not running the RPMs high enough. A slower RPM causes more shearing. That might be my problem, I'm probably on the slow side and maybe not even 1500 RPMS a lot. The post said when he went from 1500 to 2500 the shearing stopped. I'd never run mine up that high, but I might go up a bit and see if it helps.

I used to work part time on another farm bushogging the place with a Squealer "hog" the owner finally bought me a box of bolts/nuts, that thing would hit anything & shear a bolt. I learned early on to manually turn the shaft after putting new bolt in or it would shear immediately upon starting PTO back up. I was like a NASCAR guy with the changing out after a spell on account of it never quit doing it & I could reuse the nuts being they'd just fall right below the shaft when they sheared. Man, I love my slip clutch.

Ronnie

 

[bhstovall]

I agree! I love my slip clutch. I bought my first tractor last year & got a 6' Bush Hog with it. My property is pretty rough & I couldn't go 1 complete round in the pasture without shearing a bolt. I called my dealer & he ordered a slip clutch & actually gave it to me since I was having such problems. Now I would not even consider buying one without a clutch!

 

[4x4moses]

I have a Titan rotary cutter, and it shears the grade 2 bolts every time I engage the PTO. I had no choice but to move up to a grade 5. I don't recommend a grade 8, because you will lose most of the shearing safety with something that hard.

 

[QRTRHRS]

Remember to properly maintain those slip clutches. The manual for my Land Pride rototiller calls for the tension screw on the slip cutch to be backed off at the start of every season and allow the clutch plates to slip, then reset the tension screws.

When sitting idle for months at a time the clutch plates can cease together acting like a solid shaft just like some people reporting the main clutch on their tractor not releasing when depressing the clutch pedal after not being run for a long time.

I decided to sell a neighbor my 108HP Case and 15' batwing rather than move it. I told him to service the slip clutch when he went to use it come spring. He wanted to do a small patch so he went at it. Tore up two shafts and some u-joints. Whoops!

I used to use regular bolts on my Danuser 3 PT post hole digger because I broke so many especially with the larger auger. Dug a lot of holes with that over the years.

 

[Guidshir]

I busted the original shear bolt this past weekend when mowing. One thing I noticed was the yoke has space for ball bearings in the fitting. What is the purpose of the ball bearings considering the shear bolt holds them together and they don't spin?

I'm curious because I have the drive shaft and the yoke piece with the splines, but there are no bearings or rings or anything in sight. Either they never did exist or they did and were lost. Or maybe it's just a groove for grease.