Rotary Cutter PTO shaft came off of Howse Brush Hog. What now?

[AllenArmory]

Thanks for all the comments. I'll contact the dealer tomorrow. I'll answer all your questions in a little bit.

 

[AllenArmory]

Agree with RickB and Oldoak. No need for shear bolts if there is a slip clutch.

BTW, you do a adjust and maintain your slip clutch right??? Don't let it freeze up.

I have less than 12 hours on the mower and haven't done any maintenance on it yet. But yes, I will maintain the slip clutch.

 

[AllenArmory]

Go back to the idiot dealer who didn't tighten the special metric tapered pinch bolts that attach your clutch to the gearbox and tell him to get you two new ones. And let him supply them at no charge.

You're exactly right, RickB. The picture in the manual has "tapered anchor bolts."

 

[AllenArmory]

It's pretty easy to tell if they are tapered pinch bolts; The holes in the clutch will be different diameters on one side than the other. The side where the nuts go will be machined flat; the other side may not be.

I measured them with a caliper, and the holes in the clutch are the same diameter. Both sides are flat.

 

[AllenArmory]

I concur with everyone else - those are CLAMPING bolts, not shear bolts. They may or may not be the special tapered-type locking bolts that some cutter/shaft manufacturers use (like my BushHog/B&P). Howse is your best bet for the details and for correct OEM replacements (unless they confirm that they are just standard grade __ bolts).

A concern now is if the splines on either side of the joint got too chewed up to reuse.

The splines seem fine. I think the clutch just came off the gearbox after the two bolts fell off.

 

[AllenArmory]

Another pic of the clutch and bolts that fit:

 

[AllenArmory]

I was at my property this weekend and found one of the old bolts! It was sitting on the mower. The bolt head has the following on it: I CS 8.8 It does not have any lines on it, so I guess it's a grade 2 bolt like the dealer said. It's NOT a tapered bolt.

I measured the bolt at 11.70mm in diameter. It fits the clutch better than the new bolt I found at Tractor Supply, which was 7/16" (11mm).

Now, the $64,000 question, where do I find a grade 2 bolt that's 11.7mm in diameter and 3 inches long? I count 6 threads per cm, but that probably matters less, as I can always find a nut to match. My google-fu is failing me. I've tried several hardware sites, but can't find this bolt.

 

[bcp]

An 8.8 grade metric bolt is about the same as a grade 5. Metric bolts don't use the line system.

Bolt Depot - Bolt Grade Markings and Strength Chart



Take the original bolt to a hardware, auto parts or dealer, or tractor dealer, and find a match.

Bruce

 

[IslandTractor]

An 8.8 grade metric bolt is about the same as a grade 5. Metric bolts don't use the line system.

Bolt Depot - Bolt Grade Markings and Strength Chart

View attachment 507460

Take the original bolt to a hardware, auto parts or dealer, or tractor dealer, and find a match.

Bruce

Has the dealer not taken responsibility? 12 hours after prep before a major failure is not the customer's responsibility.

 

[em14]

The people in some of the post above are absolutely correct those are not shear bolts. The #5 you bought will work better than the 8.8 metric mark bolt that came out. The post above that pointed out that it appears you have not set the mechanical clutch and that is something you should do soon but for sure before you use it again. Just Google Adjust Mower PTO Clutch and you will find tons of info on how to do the adjustments. It is not difficult to do, but very important especially now that HOWSE is no longer in business! The Bolt Depot Chart is good for you to hang on too!
em14