Backhoe Broke My Backhoe

[bmac]

Stupidity has its price. Fortunately, I think I'll get off pretty cheaply on this one.

Bought may TC 29D with 756C BH back in May. Used the BH a little after taking delivery. However, a wet summer and busy schedule at work translated into little seat time and the tractor set unused for a couple of months. The BH was idle even longer.

Beautiful day today and got off work early so I decided to do a little digging. The controls on the bh were a little stiff. Smart me thinks that is because the BH has not been sused in a while. A little back and forth of the contols ought to loosen thins up. Right!

On the second or third curl of the bucket, the control handle for the curl function goes floppy on me. No response from bucket. All other functions are ok. So, after completing some loader work, I park the tractor, get out the wrenches and open things up to take a look.

<font color="red"> See Attachment for the view. </font>

 

[bmac]

Having never seen the inside of the little beast before, I didn't have a clue about what to look for. Was hoping I'd see something obviouly broken. Otherwise, I'd have to call my dealer. Boy, I lucked out as the problem could not have been more obvious.

This attachment shows the culprit

 

[bmac]

Broken bolt on the control valve linkage was the cause.

Didn't know why things had gotton stiff enough for me to break this bolt until I read in the owner's manual that this rascal is supposed to be oiled periodically.

In the attached photo the red arrow shows where broken bolt fits. Green arrow is where the oil goes, I presume.

So, by not re-reading the owner's manual, I neglected an improtant maintenance procedure which caused the linkage to bind and, thus breaking the bolt.

Now, just have to call the dealer in the AM and see if he has a replacement bolt, oil the rods, put everything back together and get back to work. Somethimes I question whether or not a dolt like me has any business owning a tractor.

Keep 'em lubed, boys and girls!

 

[DK35vince]

Just run to the local hardware store on get a grade 8 bolt the same size and length.

 

[Rowski]

My NH759C backhoe is setup the same. I've broken quite a few of those bolts in the same spot when my I was learning to use my backhoe. As a more seasoned operator I don't break hardly any. Last one I broke was a year and a half ago. I just use grade 8 bolts from my local hardware store. I also keep a few hand.

 

[Libertine]

Rowski & bmac:

Have 758c & have broken several since new (bot Jan 03 - 130 hrs). The swivel bolt also breaks. I suspect is a weakness in the design, but easy enough to fix IF you have spare on hand. I just have to learn that pulling harder on the control DOES NOT increase amount of pressure flowing to the cylinder!!! Was talking to salemen yesterday when buying set of pallet forks for FEL and he sort of implied that this is common with these. Anyway, could be worse.

JEH

 

[bmac]

<font color="blue"> Just run to the local hardware store on get a grade 8 bolt the same size and length </font>

In my area, real hardware stores are few and far between. The big box stores have come to town and put most out of business. Did manage to make it to the big <font color="orange"> orange </font> box yesterday but could not find any grade 8 hardware. Bought what they had to see if it would hold me over. Bent like a it was made of lead.

Fortunately, my dealer is a neighbor. Had my son peddle his bike to his house with the broken bolt to see if they kept these in stock. (BTW - I called first to see if it was OK) He said he has plenty so he'll bring some home with him tomorrow. I said I'd take all he had in stock.

 

[bmac]

<font color="blue"> I also keep a few hand. </font>

I will now. Thanks for the reply.

 

[bmac]

<font color="blue"> I just have to learn that pulling harder on the control DOES NOT increase amount of pressure flowing to the cylinder!!! </font>

My problem was lack of lubricant on the valve. It was binding as I tried to curl the bucket. I (wrongly) thought "aww, its just a little tight from sitting idle for a few months. Once I loosen it up a little, everything will be fine" Then the control stick got floppy.

That's when I went to the manual and read that these things enjoy a little squirt of 30 weight every once and awhile. Once lubed, the valve operated real smoothly. What bugs me a little, though, is that while oiling this is a simple task, taking that front (or rear, depending on how you look at it) plate off and putting it back on again takes a whole lot longer than the 4 - 6 squirts of oil needed make these valves happy. How often do you oil these? I've only had this thing 4 months but it has been sitting out in the weather. I know it would be better under cover, just haven't gotten the shed built yet.

Well, thanks for the comments. At least I now know (1) that oiling will help and (2) I may break one anyway.

 

[Libertine]

bmac:

<font color="blue">That's when I went to the manual and read that these</font> <font color="red"> things enjoy a little squirt of 30 weight every once and awhile. </font>

Doesn't everything.

Why do you have to take the plate off? Just lift up the rubber gasket/cover and squirt the oil (using an old oil can) on the mechanism. In fact, you can actually replace the part without removing the plate - I just did a week or so ago.

JEH

PS After reviewing your good pics, we're talking about the same part. If there was "stiffness" in the control it may not have been caused by lack of oil. The "ball" in the socket has a plastic liner which, I suspect, may have been the cause of the stiffness - sort of like arthritic stiffness in our joints as we get older, the lining fails, gets older & stiffer. The stiffness in the control arm caused you to use more pressure which then caused the bolt (connected to the ball) to shear. Same thing mine did.