Bush hog

[OHBILL]

Working on a an old Central Tractor Bush hog. Belonged to my Pa and has set for likely 30 years. He had run the wrong bolt in connection on the gear box shaft where the power shaft attached and had caused that hole to be aliitle sloppy. I added a brand new power shaft with a slip cutch. Now when i go out with it on my 5000 after a couplelaps it shears the power shaft/ gearbox bolt. Happened twice. Any ideas from the group. Ithought the slip cutch would have been more effective.

 

[E.B. Haymakin']

Working on a an old Central Tractor Bush hog. Belonged to my Pa and has set for likely 30 years. He had run the wrong bolt in connection on the gear box shaft where the power shaft attached and had caused that hole to be aliitle sloppy. I added a brand new power shaft with a slip cutch. Now when i go out with it on my 5000 after a couplelaps it shears the power shaft/ gearbox bolt. Happened twice. Any ideas from the group. Ithought the slip cutch would have been more effective.

Were there directions provided with the new shaft/slip clutch? Most new slip clutches have pre operational adjustments like loosening & then retightening the nuts bolts on the clutch to make sure it will slip. If the current bolt is a grade 2 stepping up to a grade 5 shouldn't hurt. What I'm seeing is hardly any hardware stores carry grade 2 shoulder bolts in my area. Equipment dealers are even telling owners to just use grade 5. An image of gear box shaft may be helpful, but I've had wallowed out bolt holes in input shafts and never had to replace the shaft. The cutters all rotted out before losing the gear boxes.

 

[Russ from MN]

Even though we keep our Bush Hog inside, every spring I loosen all the adjustment bolts on the slip clutch and slip it a little and then tighten it to the recommended tension. I put some reference marks on the disc so I can tell when it slips a little, we have a lot of stumps and rocks. I think the owner's manual recommends doing this.

 

[Tx Jim]

Sounds as if slip clutch needs to have spring tension loosened, plates slipped then readjusted to spec's or to the point clutch just stops slipping.

 

[farmersamm]

Same here. Thinking the clutch it too tight.

When you loosen it................run it a while, then see if it's getting hot. This tells you it's too loose. You then tighten it by degrees until it's optimal. I don't know if there's any "science" to it.......just seems to be trial and error.

 

[farmersamm]

IIRC.................the clutch on my Hesston 1410 reel clutch does have some sort of specified setting, but I'd have to look it up in the manual. Maybe your new bush hog clutch came with some sort of specs. My old Rhino doesn't have a manual, so for me it's trial and error.

 

[OHBILL]

Thanks for the suggestions. Didnot get any information with the new shaft so I will try to adjust by guess and begaully.

 

[Frankmn]

Thanks for the suggestions. Didnot get any information with the new shaft so I will try to adjust by guess and begaully.

You could put the same kind of bolt back in that your dad used. I have an old john deere mower that will break a snug fitting bolt but a sloppy one works fine. The new hole probably fits well but thr gearbox shaft is sloppy causing the bolt to shear. Sometimea a softer bolt works better than a hard one as they will bend without shearing.

 

[showcrop]

Do you have the shear-bolt good and tight? It needs the support of the shaft and yoke to not break.

 

[m16ty]

I suspect the hole being wallowed out is your problem. A shear bolt needs to fit tight to work properly. You could try a higher grade bolt, but if that doesn’t work you may have to drill it out to the next size and put a bolt in that fits the new hole.

 

[Ray,IN]

My King Kutter rotary mower uses ½" shear bolts, the gearbox shaft is hardened, so no drilling to a larger size. The ½" holes in the PTO end are elongated from shearing bolts. Since new 3" long, ½" gr 2 bolts are $2 ea. with a Nyloc nut at my local ACE hardware store I'm not going to spend over $100 for a new PTO end adapter unless it breaks.
An acquaintance didn't like replacing shear bolts, so used a gr 8 bolt. He acted sheepish when he told me he had to buy a new gearbox for over $600 after hitting a tree stump.
I know a guy that used a SST bolt, it broke. Both ends were gone, but the center section was jammed in the gearbox shaft hole by the shear. I helped him and finally got that section out with a hand sledge and drift pin; then told him " if you do this again, don't call me". The broken bolt end had gut a groove in the cast iron PTO end, so it could not be removed until that stub was driven out.
I want the easiest to replace, cheapest part to be the first to break-every time.