LA463-Sheared Loader bolt?

[RadarTech]

Ok, I did something and I just don't know what else to expect as far as damage.-
A little background may help first:

For the past couple of weeks, as time permits I have been down at our new home construction site moving dirt and rocks. this week I took a week of vacation to get many projects done and part of the time I was dumping mid-sized rocks into the carport "hole". I say mid-sized after reading some of the posts here. Most are 3-4 feet long, 2-3 feet wide and 8 inches to 2 feet think. If I had to estimate, I would say they average 200-300 lbs, with the largest being about 600 lbs- 3 1/2 to 4 feet semi round.

I didn't really think I stressed the tractor or loader- HST-L3400 with LA463 loader, until this bolt sheared. All were easy lifts, did not have problems moving any of them. Of course the read end got light now and then.....

Anyway, I am sure many of you have seen the 1/4 bolts that fit into the pivot pins on the loader support arms.

Well, I sheared one off yesterday and neither of the TWO kubota dealers I know have ever heard of it before.
I wish I had a picture of the joint, but let me try to describe it.

When sitting in the seat, looking at the left support arm from the frame moving up, you should see the first pivot point for the loader. This is the pivot in question. on this pivot pin there is a 1/4 in bolt(or metric equiv) as a retaining pin-

After expecting to be told this was some kind of special bolt, I found out it was a standard 8 8 bolt that I could get at any hardware store.
And I did, they were 36 cents each for the bolts and 33 cents for the nuts.
I bought a set of 4.....


So my questions are:
1. Anyone else ever had this happen?
2. Do you think it was just a pinched pivot pin that did it?
3. Anyone have an idea if #2 is a bad theory?
4. What other kind of damage should I expect or look for?

Thanks,
Jim

 

[LD1]

A picture would be helpfull as I am having a hard time trying to invision what bolt you are talking about.

What I think you are describing is the bolts that go through the pins and the pin bosses and are used to keep the pin from coming out and to keep it from spinning in the boss. All the hyd. cyliner pins and loader arm pins have one of these bolts.

If you sheared one, other than catching it on something, it sounds like you might have a pin siezed up in the hyd. cyl. or loader arm (which ever one is the pin you are talking about).

 

[RadarTech]

that would be it..
I will take a picture when I go down later this morning..

Thanks,
Jim

 

[kevinj]

Ok, I did something and I just don't know what else to expect as far as damage.-
A little background may help first:

For the past couple of weeks, as time permits I have been down at our new home construction site moving dirt and rocks. this week I took a week of vacation to get many projects done and part of the time I was dumping mid-sized rocks into the carport "hole". I say mid-sized after reading some of the posts here. Most are 3-4 feet long, 2-3 feet wide and 8 inches to 2 feet think. If I had to estimate, I would say they average 200-300 lbs, with the largest being about 600 lbs- 3 1/2 to 4 feet semi round.

I didn't really think I stressed the tractor or loader- HST-L3400 with LA463 loader, until this bolt sheared. All were easy lifts, did not have problems moving any of them. Of course the read end got light now and then.....

Anyway, I am sure many of you have seen the 1/4 bolts that fit into the pivot pins on the loader support arms.

Well, I sheared one off yesterday and neither of the TWO kubota dealers I know have ever heard of it before.
I wish I had a picture of the joint, but let me try to describe it.

When sitting in the seat, looking at the left support arm from the frame moving up, you should see the first pivot point for the loader. This is the pivot in question. on this pivot pin there is a 1/4 in bolt(or metric equiv) as a retaining pin-

After expecting to be told this was some kind of special bolt, I found out it was a standard 8 8 bolt that I could get at any hardware store.
And I did, they were 36 cents each for the bolts and 33 cents for the nuts.
I bought a set of 4.....


So my questions are:
1. Anyone else ever had this happen?
2. Do you think it was just a pinched pivot pin that did it?
3. Anyone have an idea if #2 is a bad theory?
4. What other kind of damage should I expect or look for?

Thanks,
Jim

The only thing that should cause the pin retainer to shear is a frozen pin which is normally caused from a lack of grease. There certainly could be some other factors involved.

 

[JerryG]

Jim,
A lot of those break within a few months of loaders being new. I have come to the conclusion that the reason they break is because they were over torqued when installed. The bolt is fractured and it eventually breaks. What I like to do is put a new bolt in and use a nylon lock nut. That way I don't over tighten it trying to keep it in place. If you don't tighten it down all the way tight, you won't ever have to replace it.

 

[kevinj]

Jim,
A lot of those break within a few months of loaders being new. I have come to the conclusion that the reason they break is because they were over torqued when installed. The bolt is fractured and it eventually breaks. What I like to do is put a new bolt in and use a nylon lock nut. That way I don't over tighten it trying to keep it in place. If you don't tighten it down all the way tight, you won't ever have to replace it.

Very good point about the torque. Most are a bit loose so they do not get stressed in normal use.

 

[N80]

I still don't know why one would break even if it was over torqued. It really shouldn't be getting any stress at all. Even if the pin is frozen I don't see how the bolt would get any stress.

Seems like it would take lateral stresses of some sort to break one of those.

 

[kevinj]

I still don't know why one would break even if it was over torqued. It really shouldn't be getting any stress at all. Even if the pin is frozen I don't see how the bolt would get any stress.

Seems like it would take lateral stresses of some sort to break one of those.

If the pin is stuck in the loader arm then it would try to rotate thus shearing the bolt. The torque issue could happen as the bolt is only 1/4" and the pins do move some in the frame so they could be twisted and snap.

 

[N80]

I Think I must be picturing things wrong in my mind.

 

[Ductape]

The only time i have seen bolts in pivot pins break is from lack of grease. Granted, its certainly possible it was weak to begin with. I would make sure you give her regular squirts of grease, and make sure you can see the grease coming out around the ends of the pins. If you keeps everything greased well, i'd call it a fluke. Replace the bolt, make sure there is a nylock nut on it, a couple pumps of grease...... and get back to work !

 

[art]

It definitely is a problem! The pivot pin will often dry up and cause enough friction to move it shearing the retainer pin. It is not common and I would moniter it in the future.

 

[RadarTech]

Here are some pics..
Image 87 is the pins with the new bolt..
Image 88 is one of many rocks I was moving!

Well, the end result is not enough grease..
I guess all the dry dust ate it..
I was hitting it about every 10 hours..



gonna watch it closer now!

Later,
J

 

[N80]

Thanks. I was picturing it all wrong.

 

[krackerjack9]

ok on that paticular pin there is no zert fiting to add grease that I know of? I used to have a L3400 a great machine. I do now have a L4400 and last week I took off the front end loader and had to pull those pins and there is no way one could even add grease if needed. Even with that on the L4400 this bolt has been replaces with just a pin that is squissed on both ends and it more or less just floats in another tab to keep it from rotating but there is no stress on it. I sort of agree with the one post that on the L3400 that the use of bolts on that model that they were over torqued in the begining and it just eventually failed.

 

[N80]

krackerjack, I think you are thinking about the wrong pin. The pin to remove the loader is below the pin he had trouble with. Look at his picture and you'll see that pin just below it.

I think the zerk fitting for the pin he had trouble with is on the underside of the loader boom....but then again I'm may be remembering things wrong again. But I'm pretty sure that pin has a zerk fitting. The pin you remove to take the loader off does not have a grease fitting.