Anyone else make the same mistake I did?

[Little Red Tractor]

I was continually popping shear bolts on a 4' brush hog, some of it when engaging or disengaging the PTO (it was an electric clutch--hard and fast on engaging and disengaging.) The clutch took care of all that pretty nicely.

 

[beenthere]

Many Shear Pins are broken due to operator error. First mistake is using Bush Hog in Reverse,
Second is cutting too low. Broken pins damaged housings, destroyed rear wheel mounts.
Keep your hand on the raise lever, and move Forward wherever possible. The front of the unit will warn you of obstructions most times.

Pls enlighten us how it is a mistake to use a brush hog (rotary cutter) in reverse??

Or is the Bush Hog brand the problem?

I do a lot of brush cutting in reverse. Mostly to see better what I am cutting and not driving over bushes and small trees that might tear up the underside of the tractor. Hate that when that happens.

 

[Williy]

JUST SOME GENERAL INFORMATION!
When you are going to use the PTO make sure
your RPM'S at as low as you can get them then
start your PTO so you don't get that sudden snap
and slowLY increase your RPM'S to what ever is
required to operate your equipment. You want
your equipment to last as long as possible with
out making repairs!

willy

 

[bearthebruce]

JUST SOME GENERAL INFORMATION!
When you are going to use the PTO make sure
your RPM'S at as low as you can get them then
start your PTO so you don't get that sudden snap
and slowLY increase your RPM'S to what ever is
required to operate your equipment. You want
your equipment to last as long as possible with
out making repairs!

willy

Or if the tractor is equiped with a soft start on the PTO, engage it. It's a nice feature on our Massey. I typically soft start at reduced RPM as Willy recommends - just maybe not as low as he goes.

 

[JWR]

I am surprised that anyone still makes a rotary cutter that does not have a slip clutch.

Size matters. The smaller hogs tend to be sold with shear bolts. OBTW, many of the shear bolts are metric or have other reasons for lacking perfect fit. Any shear bolt needs to be a tight fit. A loose shear bolt will not last long. Suggest the OP look carefully at the exact size of the bolt and make sure it is a tight fit.

 

[mo1]

Tractors MX-5400, Brush Hog (aka Rotary Cutter) Is a Land Pride 6 Footer. I broke my first shear pin after having the brush hog a year and a half (but with only about 35 hours on the brush hog) Pretty good run and it's kind of expected to break one every now and then. I looked in my garage and couldn't find any 1/2" x 3" Grade 2 bolts so went to the hardware store, no luck there, only grade 5 and grade 8, so then went to dealer and they were out. So then went to Tractor supply and bought a 5 pack of country line shear bolts and broke 3 while mowing a half hour lol.

Whether or not you shear pins or slip clutches depends on how large/heavy your cutter is relative to your tractor and what you run it through. I had a little 23 PTO HP Massey Ferguson in the past which I used with a 5' Bush Hog Razorback with a shear pin. I never sheared the pin, getting the cutter into something thick would stall out the tractor rather than shear the pin. However the same cutter behind a four cylinder John Deere with about 65 PTO HP would shear a pin so easily that you didn't even hear the engine note change if the pin sheared, you would simply see uncut brush coming out from under the mower. We always used regular grade 2 bolts as the manual specified them, anything harder takes more power to shear and we would have been shearing driveline or gearbox parts rather than 25 cent bolts if we'd used harder bolts. We reclaimed some old fallow fields full of blackberry and multiflora rose as well as numerous sycamore saplings, so we certainly sheared a LOT of bolts growing up.

I currently have a John Deere MX6 with a slip clutch behind a 5075E with a mechanical PTO clutch. The slip clutch is adjusted per the instructions in the manual. I always engage the PTO at idle so no troubles with engaging the PTO. This mower is a better match for my tractor than the Razorback was with my Dad's John Deere growing up, but the tractor is still a lot more powerful than the slip clutch can hold, so if I get into something thick like a blackberry thicket, the clutch will slip easily. A slip clutch certainly requires paying more attention to than a shear pin, a sheared shear pin causes the cutter to stop dead in the water immediately, but a slipping clutch can intermittently slip and then catch, and if it does this repeatedly through a thick clump of stuff, it can get hot enough to smoke and/or not want to hold until it cools down for a good while. You really have to be on your toes for "this doesn't quite sound right" rather than "oh, the cutter completely stopped working." I am on the fence if a slip clutch or shear bolt is better, I don't miss futzing with the PTO shaft to get it to line up so I can punch the middle third of a greasy sheared bolt out of the gearbox input shaft, and then discovering the bolt that just sheared was my last one. However, there is no maintenance for a shear bolt other than make sure it's tight and replacing a shear bolt is a lot cheaper than replacing clutch linings.