First Bush Hog Experience

[Anonymous Poster]

Hi All,

Well over the weekend I tried out my bush hog for the first time. The grass was about 2 ft. tall and since we only go there on weekends, I was behind. I have a long story but really need some help so here goes.

When the dealer brought out my tractor (TC40D) with the bush hog (Rhino SE5) he showed me how to use it. When he first engaged the PTO, there was a "pop" but he said, "Oh, that's just the paint..." Made sense to me. This was two months ago. Friday I hooked up the brand new bush hog went out to mow and it wouldn't cut anything...

Well, it was the shear bolt that "popped" on delivery, and after much reading of the boards here and the owner's manual, I bought some grade 2 shear bolts and got everything working. I mowed for the first time yesterday, taking it easy, and really trying to finese engaging the PTO.

The PTO on the TC40D basically engages full force as it is hard to "feather" the engagement. This, I think, is why the dealer sheared the bolt the first day.

Anyway, after mowing for 1 hour, I was really getting the hang of it and decided to mow a bit of the pasture. Not 20 ft into the pasture there as a "bang." I immediately pulled up the cutter and dropped the throttle. I had hit about 4 ft of rolled up barbed wire. The shear bolt sheared and was laying on the cutter.

I grabbed my spare shear bolt, but, as you can see from the attached picture, when it sheared it pushed the yoke heavily back into the gear box. In fact, the cutter still cuts and I have tried to pry the yoke forward to no avail. From the picture, you can see the remains of the shear bolt and it is actually loose in the hole, but I can't for the life of me get the yoke to move forward so I can put in a new bolt.

Is there a special tool that I can use here. Would this be a warranty item? I've got but 1 hour on my new Rhino and I've already got this major problem.

Thanks for listening...

 

[Anonymous Poster]

Here's another pic. I had to remove the housing plate just to get some room to work. IOW, the end of the yoke was rubbing on the housing plate and destroyed the plastic collar that was there as well.

 

[Anonymous Poster]

Can you drive it out with a drift pin? That is what I would try, unless there is some reason that it can't be done. If there is a reason, it's not apparent to me from the photos.

Nice close ups, BTW.

Also, are you engaging the PTO at idle or at PTO operating speed?

SnowRidge

 

[Anonymous Poster]

I can't drive it out as only a small portion of the hole is showing, and the yoke won't move.

I know it's hard to tell from the photo, but only about 1/4 of the shear bolt is showing. The yoke is jammed about 1 1/2" to the right (in photo) of where it should be. You can barely see it at the very center of the second picture. I'll find some photo software so I can circle the location of the shear bolt hole.

Yes, I engage the PTO at idle (800 RPM). I do remember the dealer, though, engaging it at about 1500 so that's probably what sheared it that first time. I really didn't have any problems when mowing and I engaged/disengaged probably 12 times.

 

[Anonymous Poster]

Here's a pic with the shear bolt area highlighted. If you look hard you can see just the edge of the bolt inside the blue rectangle.

 

[normde2001]

It appears that the shear bolt is smashed between the shaft and the yoke. I believe you are going to have to remove the u-joint, (cross and bearing), from the yoke and pull the yoke off the shaft with a fairly large gear puller. I don't believe they would consider this a warranty job. Cutting barbed wire would have to be considered abuse. To shear the original pin, at what rpm did you engage the clutch. I would engage the clutch at just above an idle and then get up to speed after you get the cutter turning.

 

[Anonymous Poster]

Here's a picture from the other side showing the shear bolt access hole. This really shows how far the yoke was pressed back toward the gear box. It would have shoved it farther but the housing support plate was there, but I removed it to get a better look at the problem as well as some leverage to try and pry the yoke forward.

 

[Anonymous Poster]

SnowRidge / Norm,

Thanks for the replys. Yeah, the gear puller will do the trick. That's the route I'll take. Hey, there was no intentional abuse here, but can you believe with 40 acres of pasture, I hit some barbed-wire in the first 20 feet and tear up my brand new cutter the first time I use it. /forums/images/graemlins/mad.gif Oh well, I can always use a good gear puller. Can't be too expensive. /forums/images/graemlins/smile.gif

 

[CTyler]

Do you have a 5-6' digging bar? You may be able to pry it loose. You may have to put a blcok of wood between the case and the bar to gain extra leverage. Either that or as suggested a puller.

 

[JackIL]

I can't quite figure out how an encounter with a wad of barbed wire could shove the yoke back. I think a possibility is that the PTO shaft is too long and that by raising the cutter to full height the yoke was driven back too far. This is an issue that the dealer should have resolved before delivery. You should be able to raise the cutter fully and not cause the PTO shaft to reach the totally closed state. Some implement / tractor combinations require that the PTO shaft be shortened to prevent this from happening. I would start with reporting this to the dealer before doing anything to try to remove the yoke.

JackIL

 

[jinman]

From the looks of things, I think I'd just keep mowing with it until it breaks loose. Since the adapter is not rubbing against the gearbox, what could you hurt? I'd bet that after a few minutes of cutting the yoke will loosen and slide forward. That's what they normally do and the snapring keeps the adapter from coming off the shaft. Heck, engage and disengage a few times at greater than 1000 rpm and that might even break it loose. I don't think anything is hurt. You have a new cutter with paint in places where it will wear off soon enough. I just think you could spend a lot of time and effort getting the thing apart and then spend money on a puller you really don't need. How would you attach a puller to it anyhow? It just looks to me like you have a homemade slip clutch which is going to let go the first time you hit something else or high-center on uneven ground. My suggestion is to give it a go and let it work itself loose.

 

[Slippy]

I had just about the exact same thing happen to me with my first cutter the first time I used it, although I did not hit any wire. Best I could figure I hit a rock. Anyway, the pin sheared as yours did, and it stuck except mine was on the off side of the shaft, or in other words, closer to the tractor like it was trying to come off. I did what jinman suggested after trying everything I could to get that thing off. I tried the pry bar, block of wood, I even tried hitting it with a block of wood and a small sledge hammer. I knew I had to be careful becasue I did not want to damage the seal in the gear housing on the mower. Finally I gave up and just started mowing. I'm telling you, I could hit a steel post and that thing would not move. It was almost as if it welded the shaft and the yoke together. Anyway, after mowing for a while I called the folks who made my cutter and they sent me a new gear box and yoke, no questions asked. I put it on and have not had any problems since. I can tell you the old gear box and yoke are still sitting in my barn, still welded together. All I could figure was it was not going to come apart and something else was going to break before it would, and then there would be no way the warranty would cover it. So, my suggestion is that you call the manufacture or dealer. It doesn't matter if you hit wire, rock, steel bar, or anything else. It is designed with a shear bolt to permit it to break before something else does, no matter what you hit. It is foreseeable to the manufacture that you are going to hit things, thats what the shear bolt is for. As long as you used the size and strength of shear bolt as suggested by the manufacture, they should send you a new one.

 

[Anonymous Poster]

JackIL,

We'll I'll check the shaft length, but I don't think that is the problem. I've had the cutter raised to full height several times I'm pretty sure. Plus, when reading through TBN on shear bolts, there were some threads on shaft size as being a problem, which is why I checked it. However, I was primarily checking to make sure I didn't BEND the shaft at full height.

There is another foggy detail on the break. I remember hitting the barbed-wire, lifting the cutter, and disengaging the PTO. I got off the tractor with a new shear bolt in hand, but when I got there, the bolt was fully intact. I thought to myself, cool, it didn't shear. I got back on the tractor and engaged the PTO (at idle), and then it popped. I got off and sure enough the bolt pieces were laying on the cutter. So I'm guessing the hit really weakened the shear and finally snapped when I engaged again, and this may be the primary difference with this particular shear (compared to a "normal" one?).

Jim,

Yeah, your plan sounds good too. And to be truthful, when I was trying to move the yoke, I decided to mow a little bit around the barn. I thought, darn, surely a few PTO engages should loosen this up. It didn't so I decided to mow a bit as that would surely loosen it. I kep thinking "What if I hit something and bend the tractor PTO..." so I only mowed for about 5 minutes.

Slippy,

You bring up a good point too in that it may be on there so hard that it may never move and the next time I hit something, I may damage something more expensive and I'll be the one to blame.

So I'll call the dealer and the manufacturer this week, and if I don't get any resolution by the weekend, I'll try some more mowing to see if it loosens up any.

Thanks all,

 

[Bird]

I'm not sure what you should do, but I know what I, personally, would do. I would get two crow bars (wrecking bars?) so I could pry equally on opposite sides of that yoke and try to pry it forward. And if that alone didn't do it, I'd get a torch (in my case I'd probably use a propane torch) and heat the yoke all the way around; not a lot but just enough to make the metal swell a tiny bit. And I'd remove that snap ring on the front end of the gearbox shaft so I could completely remove the yoke and clean the surplus metal from inside the yoke and the outside of the input shaft that I'm confident the shear bolt left in there.

 

[JohnMiller3]

Between some paint on the gearbox input shaft and some metal remnants from a mushroomed end on the partial shear bolt jammed into the shaft… looks a little “stuck”… /forums/images/graemlins/shocked.gif

As already been mentioned, verify the length of the PTO shaft as being right (so you don’t start fighting multiple battles here), confirm the snap ring is still in place on the gearbox shaft (from the picture, it looks ok), and now back over some real brush (multiple ¼ - ½ “ stems grouped together) and start cutting a few minutes while going forward slowly, between the heat created on the shaft and the “brush load” under the cutter, now should allow movement of the yoke on the gearbox input shaft…

As a last resort, shut down the tractor altogether, with the rotary cutter sitting on the ground (with the blades into some thick uncut brush-acting as a load), remove the snap ring, use a crowbar inserted in the forward side of the yoke (tractor side-gearbox end), with some muscle, twisting and pulling the yoke into position to replace the shear bolt, or off entirely to clean up the under surface to prevent future jams… /forums/images/graemlins/smile.gif

This is no big deal… just some initial aggravation with muscle/sweat and patience needed to resolve…

 

[JohnMiller3]

Hi Bird,
/forums/images/graemlins/wink.gif

Either you're a faster typist... or I'm a slower coffee drinker... /forums/images/graemlins/smile.gif

/forums/images/graemlins/laugh.gif

 

[looch]

If you can get your hands on a puller, you could at least give it a try.

This is another option that worked for me when I was in a similar situation (no puller and on a Sunday with a driveway full of snow). You may or may not want to try this - a bit fidgity and I just happened to have all the necessary trinkets on hand.

I took 3 set screws, each just long enough to fit between the shoulder of the yoke and the gear box. I screwed to nuts onto each set screw and and dropped them into place. Using an open end wrench, I unscrewed the nuts which in turn forced the yoke to move away from the gear box. When they were unscrewed to the max, I simply got longer set screws and repeated the process. Eventually, it was loose enough to remove the rest of the way with a block of wood and light raps with a hammer.

I now relieve my shear bolts right where shaft meets yoke. I just make a vee using a file. This eliminates the "smearing" that can happen to the bolt making it difficult to get shaft out of the yoke and getting the bolt pieces out of the hole.

 

[boustany]

I would see if I could borrow or rent some (I think they are) ball joint pullers. They look like wedges with a 'U' cut in them. You whack the wedges toward the center. They generate a tremendous amount of force due to the slope of the wedges and the force of the hammer blow.

Those tools are pretty cheap and would probably be easier to use than a puller, which would want to slip off all the time. Make sure you get a pair big enough to slip around the shaft.

Plus you could start by tapping and graduate harder and harder hits if it didn't come off.

That's what I'd try, anyhow...

 

[kensfarm]

Shaft length - I saw a Boomer last year at the dealer that had been almost totally disassembled.. lot's of pieces parts. The mechanic said the owner didn't check/measure the length of the PTO shaft on a new attachment.. ended up pushing the tractor's PTO unit into the tractor.. breaking the internal housing structure.

PTO engaging - on my TC35D.. the PTO will start engaging at the midway point.. the engagement lever is tuff.. I have to use two hands to slowly engage.. I watch the safety shield for movement.. let it start rotating.. then fully engage. I do this for the trim mower & the rotary cutter.. but not for the PHD or the tiller.

Hopefully a puller will do the trick.. I know some auto-part stores rent some tools.. like puller's.. could be a good alternative to buying.. but if there's more barb-wire laying in wait.. you might use it more then you want. Best of luck!

 

[Anonymous Poster]

Hearing about hard engagement of the PTO - I guess my TC18 really spoils me - first with all the safety interlocks that make it hard to get in trouble (see safety discussion), and then with PTO engagement - push in the clutch, engage the PTO, let the clutch out slowly, it starts to turn and you control it.

Nice when you get in some really thick grass or something that threatens to stall the tractor - just dump the clutch (which stops power to the PTO and stops motion by the hydro faster than letting up on the treadle), disengage PTO, let out the clutch, back up a little with the hydro, and repeat to re-engage PTO.