Here is what happens when you have the wrong shear bolt

old · Oct 20, 2016

So got a call this morning form a friend who had a U-Joint break on his brush hog. It will be costing him a good bit more then just replacing the U-Joint because it had a grade 8 bolt in the place of the shear bolt. Notice the U-joint is broken and both sides are a fresh break. In the 2nd picture notice the yoke on the shaft end is a lot wider then the shear bolt yoke so I will have to replace the yoke in the shaft which I got lucky and it a simple roll pin to remove it and I hope I can find a replacement for it

jon f mn · Oct 20, 2016

He may be using bolts that are too hard, but I doubt that would cause that kind of failure. I would bet with adequate questioning you qill find something else caused it.

Pair-a-dice farm · Oct 20, 2016

Yep a G8 bolt don't make a good shear pin. However that yoke is repairable. I've straightened several that were in as bad or worse. A good vise and a little finesse will straighten it up.

old · Oct 20, 2016

He hit a stump and being who he is and the type of problems he has it is likely to have hammered that stump for a couple minutes before he was able to get the hog up and off of the stump.

He had a stroke a few years back so he has lots of problem getting around and doing things. A few week back he called because he got it stuck and I went over and found he was low on hyd fluid and once I added some I was able ot get the loader up and the hog up and use the brake to get it out

old · Oct 20, 2016

Every one I have tried to repair has either broken or would over time bend back and since this guy has health problems I'll replace it so he is less likely to have problems in the future

Fred Werring · Oct 20, 2016

Dad had put a grade 8 in a bush hog too, and with the same results.

Fred

old · Oct 20, 2016

My worry is that he may have also hurt the gear box and if he did well all he will have left is scrap iron hog

jeffcat · Oct 20, 2016

The other thing that will bust them up is lifting the mower's deck up into the drive. Just a little tooo high. Have seen the aftermath of someone running am MTD snow blower and the dumb kids left something in the drive. Shear the bolt and the only thing the guy has around is a bolt from a mower deck or something from a friends boat or such. You do find out that little gray metal gear box on the front can cost from $150 to 200 for just the part. Robery . Pack of sheer pins that everyone with an MTD should have. Even better on this would be putting a grease fitting where 5he sheer pin is so when it breaks it doesn't chew evertything up. I make my own sheer pins with a #2 bolt and take youre angle grinder with an .o45 disk on it and buzz two littl groves into the bolt. Break a little easier so make some spares. Sure saves gear boxes and teaches you to be just a little more carefull.

farmerwithmutt · Oct 20, 2016

I bought a landpride that was a rental never thought to check but someone had done the same thing. Fortunately the dealer covered it and I actually got a new shaft. Check the knives those also had damage on mine.

JOCCO · Oct 20, 2016

Old: my thoughts are these days it is often cheaper, faster to just get a whole new shaft cut it to length and your done. Repairs cost more than new shaft!!!!

old · Oct 20, 2016

New yoke and u-joint at Orscheln's should cost less then $30 where as a whole new shaft will be around $100 or more

ditchwitch · Oct 20, 2016

Tell him there is actually a reason for that shear bolt. If it required a grade 8 bolt i am sure the factory would have installed one. But in his defense the shear might have broke out in the field doing another job and thats all he had to get it going to finish up. And just forgot to replace it. It happens to all of us.

Dick · Oct 20, 2016

Your idea of making the cuts on a #2 bolt sounds like a good idea. Could you be more specific about where you make the cuts on the bolt? A picture would be nice but if not possible maybe you could let us know where on the bolt you make your cuts. I wouldn't think it would be in the middle of the bolt, but since you've used this technique you will know where is the best place.
Thank you,
Dick

Traditional Farmer · Oct 20, 2016

Shear bolts are a poor substitute for a slip clutch on a brush hog anyway.

Texasmark1 · Oct 20, 2016

Opinion, not shared by all!

Texasmark1 · Oct 20, 2016

My 1991 JD 375, 5x4 round baler specifies ?" Grade 8 in the JD owner's manual. Caveat here I think, is that the drive line is a Cat 3, like 100+ hp drive and ?" for that size line is pretty small. My 6' shredder has a ?" on a Cat 2 65hp med duty gearbox. That one gets a grade 2.

One thing I learned is that you use a locking nut and let it run loose rather than torque it down. Pins last a lot longer that way for me anyway.

old · Oct 20, 2016

I have seen as much or more damage done by slip clutch set ups. If set wrong or been setting a long time a slip clutch can/will lock up tight and cause that and much more like the JD 1020 I have in the shop that had the PTO coupler break into 5 pieces because the slip clutch did not let loose like it should have

Traditional Farmer · Oct 21, 2016

Slip clutches will work and will work like they are supposed to if adjusted right.Now just like putting gasoline in a diesel engine nothing is totally Idiot proof.

rad · Oct 21, 2016

Interesting. When I bought my JD brush hog, thy gave me a handful of shear pins (bolts). They would shear off when the mower was raised off the ground and the engine was not running more than 1000 RPM. I should add I was not popping the clutch. When I complained, the dealer told me to use grade 8 bolts. I refused unless they would give me a letter from JD that said to use grade 8 rather than what was recommended in the manual. Most surprising, I did get the letter and have been using grade 8 bolts for the past 19 years. Guess your mileage varied.

Case Nutty 1660 · Oct 21, 2016

easier fix than on one of mine I loaned out and the guy hit a old water well casing,,, I had just adjusted my pto clutch as it was slipping when I was cutting heavy sage brush,, that one broke my PTO drive shaft so I had to split it to replace,, she has only soft bolts again now,, seen this a LOT when I sold mowers,, also seen the drive lines fail when they bottom out but that shows easy as it always twist the yokes much worse,, I agree with a slip clutch is much better but like stated you have to Maintain them just like keeping the correct grade bolt in this type
cnt

old · Oct 21, 2016

A slip clutch just like a shear pin will or will not work and either one can not work when it should. Seen slip clutches so rusted up that you could take the bolts and spring off and it still would not slip. Or one where the springs where removed and bolted up tight. NO safety device will work 100% of the time and the only safety that might work correct is the one between a persons ears and now days those seem to not work a good bit of the time

old · Oct 21, 2016

Many factors come into play on these things. This brush hog looks to be a King cutter or some such brand so who knows what should be there and for that matter what all happened to get it to this point.

Traditional Farmer · Oct 21, 2016

Like I said equipment needs to be kept in working condition a rusted up slip clutch has not been kept in working condition or some fool bolting them up solid they deserve to have their machine torn up.Any machine is only as good as the operator.

old · Oct 21, 2016

Note that I said the only safety that will work right all the time is the one between a persons ears and many time that does not work.

In the case of the JD 1020 the slip clutch did not work because some one bolted it up tight. So the guy that brought this 1020 and hog set up did not know the difference and did not know that it even had a slip clutch. When I get done with this tractor he hopes to install bot ha shear pin and also fix the slip clutch so that way maybe one of both will work when it is needed

Traditional Farmer · Oct 22, 2016

If the slip clutch is working right it'll slip a little on a hard impact every time thus keeping from damaging the tractor and a slip clutch will need replacing if its working right every so often,but that's a whole lot cheaper than repairing the PTO on a tractor.Also you need to tell the fellow to get owners manuals on all the tractors and equipment he buys and read them.

Here is what happens when you have the wrong shear bolt

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Similar threads