Brush Hog, Slip Clutch, and Shear pins

[IronShepherd]

Hi All,

I called the manufacturer of my brushhog and asked about putting a slip clutch on.
They said they don't make one for it and its not recommended because its not "heavy" enough.

Im not sure what heavy enough means, not heavy duty enough? Forgot to ask during the call...I went to a local big name tractor dealer and told them what I was looking to do they didn't seem concerned about what the manufacturer said and we ordered the slip clutch...I did not buy the brush hog from this dealer....I haven't picked up the slip clutch yet either, Im not sure Im having regret or not about ordering.

Im looking to cut heavy weeds, thick grass, and young trees maybe an 1/2-1" thick. The problem has been the terrain is bumpy right now other wise the brush hog has done the job.
But when the tractor gets on uneven terrain the mower blades hits, the shear pin goes to bits. Ive been through 8 pins (number 1s) in 4 hours of mowing. It's gotten so bad I am not replacing the yoke on the drive shaft nearest the mower gear box. However Ive been trying to keep the areas somewhat groomed until I can get a dozer to fix the uneven areas. I know that's the issue but no money for the dozer at this time.

I haven't had a blow out in the last hr I mowed, I kept the mower deck higher off the ground but the back wheel isn't touching but its working ok...just doesn't seem safe so I stopped.
Im not sure what to do at this point. Im very concerned about wrecking my tractor PTO, any advice?

Thank you,
Shepherd

 

[1980 F1500]

I've done a lot of brush cutting with my JD 413, and I know what you are talking about. You didn't mention the brand or size of mower so it is not easy to determine what your cutter is capable of. Are you using the TC45D for the cutter. If you can, lower the rear wheel of the cutter and keep the front skid plate of the mower above the level of the ground. You want the front cut about an inch lower than the rear. You may be able to go a bit harder on the bolt shear strenth. As to safety, no one else should be around while cutting. You can get a chain or rubber guard for the front of the cutter to protect yourself. This should get you by until the ground is evened out.

 

[SPYDERLK]

Slip clutch is a good idea. Adjust it in use after you get it in the ballpark via spring compression instructions. The clutch must never slip [should stay cold] with the vegetation you describe, essentially no more than grass to a bushog. It should slip tho in the conditions that were breaking your shear bolt. Duplicate a couple of those and stop quickly and feel the clutch. A little warmth is good. Dead cold or hot is not. Adjust to suit.
larry

 

[IronShepherd]

I've done a lot of brush cutting with my JD 413, and I know what you are talking about. You didn't mention the brand or size of mower so it is not easy to determine what your cutter is capable of. Are you using the TC45D for the cutter. If you can, lower the rear wheel of the cutter and keep the front skid plate of the mower above the level of the ground. You want the front cut about an inch lower than the rear. You may be able to go a bit harder on the bolt shear strenth. As to safety, no one else should be around while cutting. You can get a chain or rubber guard for the front of the cutter to protect yourself. This should get you by until the ground is evened out.

Its's a LMC Andy 600 6ft mower, yes, I'm using the TC45D. No one is around when mowing but when I did hit the dirt sometimes rocks come flying out and they do travel some distance.

Thank you for the advice its much appreciated.

 

[IronShepherd]

Slip clutch is a good idea. Adjust it in use after you get it in the ballpark via spring compression instructions. The clutch must never slip [should stay cold] with the vegetation you describe, essentially no more than grass to a bushog. It should slip tho in the conditions that were breaking your shear bolt. Duplicate a couple of those and stop quickly and feel the clutch. A little warmth is good. Dead cold or hot is not. Adjust to suit.
larry

Will do...thank you for the advice.

 

[Soundguy]

slip clutch, properly adjusted is an UPGRADE from a shear pin. do't feel bad about it.

but DO maintain it.

an unmaintained slip clutch is like NO shear protection..

 

[jinman]

Remember, a slip clutch or shear bolt is for when things happen that you don't expect or foresee. Many/most of us mow rough areas. The object is to adjust the height of the mower so the instance of needing a shear pin or slip clutch is rare. From your description, I think you need to lower that rear tire so your mower has a higher set and also raise your 3PH. For the first rough cut, 6" off the ground is good. That should get you above most mounds.

I've hit many things while mowing and popped dozens of shear pins, but normally no more than 2 a day and most times less than 2 a week. If you are breaking more on a regular basis, you are doing something wrong and your equipment will suffer, most likely not the tractor, but your mower will soon start failing, maybe a weld or a bolt will snap on a support. It's just advice, but my best suggestion is to raise that cutter and find out what is there without letting the emergency protection devices take a beating.

 

[SPYDERLK]

Actually, with a bushog I prefer to chop off the mounds. 10HP per foot does pretty well in low gear. Why mess around?

 

[IslandTractor]

I have used both shear bolts and slip clutch on bush hogs. I initially thought shear pins were a pain in the butt but after switching to a slip clutch I have to say that I spend more time maintaining the slip clutch than I ever did changing shear bolts. If I was using a cutter regularly year round, I'd certainly go with the slip clutch. However, I use my bush hog seasonally and therefore need to reset the thing every spring. Takes maybe 30-40 minutes. Only takes about 5-10 minutes to replace a shear bolt in the field.

 

[SPYDERLK]

I have used both shear bolts and slip clutch on bush hogs. I initially thought shear pins were a pain in the butt but after switching to a slip clutch I have to say that I spend more time maintaining the slip clutch than I ever did changing shear bolts. If I was using a cutter regularly year round, I'd certainly go with the slip clutch. However, I use my bush hog seasonally and therefore need to reset the thing every spring. Takes maybe 30-40 minutes. Only takes about 5-10 minutes to replace a shear bolt in the field.

I dont maintain the one on our 60" 127 Gyramor other than put a little grease in its fitting a few times. Ive had to tighten it up a couple times over the years when it would get slippy. Id say the time invested over 40+ years has been less than an hour.
larry