Bush Hog shear bolt
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=173188
Printed Date: 26 Apr 2025 at 9:24pm
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Topic: Bush Hog shear bolt
Posted By: allischalmerguy
Subject: Bush Hog shear bolt
Date Posted: 29 Jul 2020 at 8:08pm
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I have a bush hog 5 ft rotary mower. I pull it with my D17 and WD. What do you recommend I put in for a shear bolt in the bush hog so I don't tear up the pto in my tractors? Grade 2 or Grade 5? Thanks Mike Townsley ------------- It is great being a disciple of Jesus! 1950 WD, 1957 D17...retired in Iowa, |
Replies:
Posted By: steelwheelAcjim
Date Posted: 29 Jul 2020 at 8:13pm
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Grade 2. Assuming you have a smooth shaft yoke with a 1/2 inch shear bolt, and you don't have a slip clutch. You want the bolt to shear before the gearbox suffers damage. If you continue to shear bolts on a regular basis, you might be cutting too close to the ground causing scalping, or not allowing the cut trash to escape from under the mower. A harder bolt will delay shearing and cause potential gearbox damage.
------------- Pre-WW2 A-C tractors on steel wheels...because I'm too cheap to buy tires! |
Posted By: ac45dave
Date Posted: 29 Jul 2020 at 8:14pm
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Mike what brand and model mower do you have?Bush hog brand was pretty good about building in safety devices from the factory whether it be a shear bolt or slip clutch.Some pics would help also to see what you have. ------------- 54 wd-45gas ; 56 wd-45d N/F w/fact p/s ; 63 d-17 sIII N/F gas ; 60 D14 N/F ; 67 d-17 sIV N/F gas ; 63D15 sII W/F; 39rc#667 ; 2021 massey 4710 fwa ; gravely 2 wheel tractors |
Posted By: ac45dave
Date Posted: 29 Jul 2020 at 8:16pm
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Slip clutches need to be adjusted to the tractor HP to properly protect it. ------------- 54 wd-45gas ; 56 wd-45d N/F w/fact p/s ; 63 d-17 sIII N/F gas ; 60 D14 N/F ; 67 d-17 sIV N/F gas ; 63D15 sII W/F; 39rc#667 ; 2021 massey 4710 fwa ; gravely 2 wheel tractors |
Posted By: allischalmerguy
Date Posted: 29 Jul 2020 at 8:16pm
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ACDave It is a Bush Hog built one. I don't think it has a slip clutch. Just a shear bolt. Thanks! Mike ------------- It is great being a disciple of Jesus! 1950 WD, 1957 D17...retired in Iowa, |
Posted By: ac45dave
Date Posted: 29 Jul 2020 at 8:19pm
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I always got my shear bolts from my dealer when I had a shear bolt type mower.That way I knew I had what was supposed to be in there.Not sure what grade they were. ------------- 54 wd-45gas ; 56 wd-45d N/F w/fact p/s ; 63 d-17 sIII N/F gas ; 60 D14 N/F ; 67 d-17 sIV N/F gas ; 63D15 sII W/F; 39rc#667 ; 2021 massey 4710 fwa ; gravely 2 wheel tractors |
Posted By: truckerfarmer
Date Posted: 29 Jul 2020 at 10:16pm
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I was told use grade 5. Grade 5 will break clean, grade 2 will 'smear', making them hard to get put. ------------- Looking at the past to see the future. '53 WD, '53 WD45, WD snap coupler field cultivator, #53 plow,'53 HD5B dozer Duct tape.... Can't fix stupidity. But will muffle the sound of it! |
Posted By: Boss Man
Date Posted: 29 Jul 2020 at 10:20pm
| Borrowed a guys brush hog and put it on a 170. He had put a grade 5 in and I twisted the telescoping PTO shaft. I took out several Grade 2's but didn't damage anything. When I bought my brush hog I spent the extra for the slip clutch. I loosen the clutch springs in the spring and make sure the disks aren't stuck then I'm good for the summer. |
Posted By: allischalmerguy
Date Posted: 19 Aug 2020 at 6:02pm
Thanks!! ------------- It is great being a disciple of Jesus! 1950 WD, 1957 D17...retired in Iowa, |
Boss Man wrote:Posted By: TramwayGuy
Date Posted: 19 Aug 2020 at 6:25pm
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“ I loosen the clutch springs in the spring and make sure the disks aren't stuck then I'm good for the summer.” That’s the best thing you can do with the slip clutch style! |
Posted By: Jim.ME
Date Posted: 20 Aug 2020 at 6:36am
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I don't know what model you have, but here is a clip from one of their on line operator's manual. Many of their manuals are on line, or you can contact them and I think they will provide older manuals if needed. "SHEAR BOLT or SLIP CLUTCH DRIVELINE INSTALLATION
Attach rear driveline of U-Joint to input shaft on gearbox, install snap ring in groove on input shaft.
NOTE: Check that Snap Ring is properly seated in groove.
This snap ring retains driveline when shear bolt shears. Install Grade 2 (only) shear bolt 1/2” x 3”. Use of a
stronger shear bolt other than Grade 2, will result in driveline failure and will void warranty." (Not that I think you are concerned with warranty.)
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Posted By: Rick of HopeIN
Date Posted: 23 Aug 2020 at 11:58am
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Old Deere balers had the right idea, they used a small dia hardened bolt that would shear clean. Also not much chance a farmer would find a harder bolt off the shelf to replace it. ------------- 1951 B, 1937 WC, 1957 D14, -- Thanks and God Bless |