toplink bracket problems

[bert2755]

Can anyone tell me what the proper torque spec would be for the top link bracket on a JD2755? Really bad day yesterday, broke 2 TL brackets!

Are the aftermarket TL Brackets any stronger then the JD ones?

Thanks in advance, very interesting forum, I think I will spend lots of time reading here.

 

[RoyJackson]

How on earth did you break toplink brackets?

Anyway, if you know the thread of the bolt (or take one to a hardware store for comparison), go on line and look up torque values. Torque values are normally based upon the thread size (1/2-13, for example) unless specifically called out for a particular application.

 

[beenthere]

:welcome:
I'd also like to know more about the broken brackets. Can you post a pic or two?

Need to learn from your experience.
Thanks

Is this the bracket? Seems if it is, there are some mating surfaces that are getting in the way to cause it to break. Or, what implement is being used? Maybe a subsoiler?

 

[bert2755]

using a tree spade 44 " BaumaLight with a 3 point adapter. The first bracket broke I believe when I went over a bump too fast and the tree spade may have drug on the ground, that is my theory anyway. Changed that bracket out with a spare one that I had here (which is a whole other story about non standard JD toplinks). But I reused the bolts that were out of the broken one.

The second one, a bolt broke off and the TL bracket self destructed very shortly thereafter. So we are thinking the bolt may have been stressed during the first incident. At least that is my thoughts right now. But I can't help but wonder if one of the bolts were not tight enough and caused the TL bracket to flex (which cast does not do well).

The bracket shown in the pic is the one I have (had).

 

[beenthere]

Maybe it is the "weak link" in the system to protect something more major.

A tree spade may be beyond the practical limit. But can only surmise from what you have explained. From my limited experience using a tree spade on a truck, there were some serious side, forward, reverse and lifting stresses put on the truck chassis when trying to get the spades shoved into the ground to get a tree.

 

[bert2755]

i had considered that too, but the first 50 or so trees when well. Then I bought a second TLB and drilled it out to fit a standard cat 2 TL pin and installed it. Right after this I started to have problems. The TLB did not break where I drilled it out. The fact that these brackets broke only after I changed them. Therefore it is something I have done.

 

[beenthere]

Interesting.
Can you post a pic of the broken one(s) ?

 

[magicheater]

Interesting.
Can you post a pic of the broken one(s) ?

Yeah! I would like to see that too. I built a custom top-link bracket for my L4350 using the standard mounting pattern of the original, it weighs about 3 times as much, I just check to make sure the bolts are tight regularly, has only come loose once in ten years. Thinking of building one for my B7800 as I want to try to duplicate an experiment I did on the larger "K" and see if it has any merit.

 

[bert2755]

here are some pics. The first 3 are of the bracket that I drilled out to 1". Ignor the welding, I was just playing to see what happens when you try to weld cast.

The forth pic is from my original bracket that I also broke after the new one broke. Not to sure where the rest of the parts are for that one right now (may be in the bush somewhere). As I recall there may have been a touch of rage going on after the 2nd one broke.

Neither of the brackets broke where the pins go. The first one just blew out. The second one looks like a bolt broke and the bracket busted up after that. I had reused the bolts from the first one and suspect that they may have been weekended or had hairline cracks.

Any idea's whats going on here?

 

[beenthere]

My idea is you are using an attachment that needs a category II tractor ahead of it.

 

[chopped]

Goodness. I have broke one of those on a holland in my 35 plus years.. I was mad at first (it was my miss use). But then when I figured a 60 dollars bracket was way better than a torn out upper casting, I am happy. I hope mine tears out before it does more damage. Like someone said the weak link. I would prefer to call it a shear pin.

 

[magicheater]

using a tree spade 44 " BaumaLight with a 3 point adapter. The first bracket broke I believe when I went over a bump too fast and the tree spade may have drug on the ground, that is my theory anyway. Changed that bracket out with a spare one that I had here (which is a whole other story about non standard JD toplinks). But I reused the bolts that were out of the broken one.

The second one, a bolt broke off and the TL bracket self destructed very shortly thereafter. So we are thinking the bolt may have been stressed during the first incident. At least that is my thoughts right now. But I can't help but wonder if one of the bolts were not tight enough and caused the TL bracket to flex (which cast does not do well).

The bracket shown in the pic is the one I have (had).

Please read page 2 I think this is where the problem is and not the bracket.

 

[beenthere]

From page 2....

Unit weight is supported by a rigid top link. Movement of link arms is eliminated and replaced by two powerful cylinders.
This will take full advantage of the entire tractor weight and gives you down pressure currently unavailable on your tractor.
Operator must ensure adequate strength of top link bracket on tractor.

Magic
I think you did find the source of the OP's problem. And prolly why he is looking for a beefier bracket to replace the Deere OEM.

 

[magicheater]

From page 2....



Magic
I think you did find the source of the OP's problem. And prolly why he is looking for a beefier bracket to replace the Deere OEM.

Then I suggest building one to suit the need. Just make sure you use long enough bolts if you beef up the plate some. That is what I did for my application. Please excuse the dirt, I have since power washed the tractor.

 

[bert2755]

The hitch on this tractor is a Cat II hitch. The lift links are standard Cat II size and the implement end of the JD supplied toplink is also the standard Cat II size. The only reason to drill the bracket out a bit is that the JD supplied pin is not Cat II , nor is it Cat I.

Plus the fact that I have moved many trees with out any problem until I changed the bracket. Both times the bracket broke, it only had the dirt ball in it, no tree.

Now, I did notice last night that the lock washers on the bolts that were in there were also flat (fatigued). So they had no ability to hold the bolts from loosening off.

Basic question still remains, does anyone know the proper torque spec for these bolts?

If the bracket breaks, it breaks. I just want to make sure it's on correctly.

Thanks for all the info so far - great forum.

 

[RoyJackson]

Basic question still remains, does anyone know the proper torque spec for these bolts?

Let's try this again...
If you cannot find a specific torque for a bolt, use the standard torque value for the thread and grade of bolt. So, you need to know the thread pitch/size (such as 1/2-13).
And, don't use lock washers if you're going to torque the bolts.
This chart might point you in the right direction:
http://www.portlandbolt.com/technicalinformation/bolt-torque-chart.html?gclid=CLGxyvu-sqMCFRdo5Qod_zvmBw

BTW, before you install those bolts, inspect the female threads in the casting. They might be pulled.
We had a component returned by a customer a day or so ago. The threads were pulled so badly, there was no way torquing was going to work...there just wasn't enough thread left. This was an M20 or larger thread (used on a light-rail transmission gearbox). The bolt was fine (but I don't know if the bolt returned with the gearbox was the bolt shipped with the gearbox). We're still trying to figure out how they could have done that...this was some serious overtorquing. The threads weren't stripped...it was if the bolt was installed and pulled straight out.

 

[Tunguska]

Roy - Not to get too far afield on this thread, but there was an incident in Baltimore a few years ago where the MTA buses were breaking studs and losing their wheels.

Turns out the "mechanics" had their air wrenches set at some tremendous torque (400+ ft./lbs. in some cases) and didn't know it. I hope they weren't working on the gearboxes you mentioned!

 

[RoyJackson]

Roy - Not to get too far afield on this thread, but there was an incident in Baltimore a few years ago where the MTA buses were breaking studs and losing their wheels.

Turns out the "mechanics" had their air wrenches set at some tremendous torque (400+ ft./lbs. in some cases) and didn't know it. I hope they weren't working on the gearboxes you mentioned!

This work was done in Philadelphia or it's suburbs. This is the only one like this (of a couple hundred shipped).

 

[bert2755]

Well the new bracket came in yesterday and I installed it. Went with the rated amount of torque of about 150 lbs. Inspected the threads first seem fine and held at 150 lbs. I did use new bolts and new lock washers (which just become a spacer after 50 lbs IMO) so we will see what happens.

And just for a complete piss me off the A&I bracket was about 1/8 inch narrower then the original JD brackets so my tree spade would not slide back into the new toplink last night anyway (2 hours wasted trying). Was going to go and touch it up with the grinder tonight but it's rain'in so hard right now that I ain't going out!

thank god for beer!!!

I keep the post going just so others can learn from my stupidity.

 

[beenthere]

Don't see anything stupid that you've done.
But thinking if I was to grind something, it would be the tree spade arm (is it like a top arm?) and not compromise the bracket strength. But hope it all works out for you and all your effort so you can get back to moving trees.