Broken top link mount

GaryMc · Apr 21, 2015

I recently purchased my first tractor, a used B3030. After using the box blade for a little while I noticed that a bolt for the top link mount bracket on the transmission was loose. After a closer examination I discovered that the problem was a lot worse than a loose bolt, see pictures. Does anyone know a fix for this situation other than replacing the transmission casting that's broken? Is there a one piece bracket that could be mounted with just 3 bolts but had enough structural integrity to support the tensions applied by the top link? I was thinking of having something fabricated on a piece of 1/2" steel plate that would provide the same hole patterns for attaching the top link. Please share your thoughts, ideas or concerns. Any ideas what could have caused this to break?

Thanks,
Gary

FTG-05 · Apr 21, 2015

I take it the seller failed to disclosed this little failure?

Too bad its the top bolt and not one of the lower ones, it would be a lot easier.

Good luck.

Milo Holroyd · Apr 21, 2015

At first look, and not being familiar with your Model Kubota, I would offer this:
1. If there is enough depth in the casting, drill and tap the hole deeper.
(you'll have to have a spacer to compensate for the broken piece)

2. Drill and tap a new hole closer to center. (that's where all the pull is anyway)

3. If there is enough casting on top (above the broken hole), consider a bracket that goes from the bottom hole, up, and over to a new bolt hole.

All is not lost

bxray · Apr 21, 2015

A solid piece with an "L" catching the bolts on the bottom where the dipstick is would be a start.
And Welding the flanges to it.

ShaunBlake · Apr 21, 2015

Gary, so sorry for this discovery. It's clear that the guy who broke it tried to patch it with something similar to JBWeld, so he's culpable, he should have informed you. I suspect it's changed hands in between, and the last seller didn't realize the significance.

I can't find the part on KubotaBooks.com's parts list (I'm totally ignorant about your model) but I'd like to suggest two things:
1) Call West Kentucky Tractor Parts and your nearest/favorite Kubota dealer and ask for availability and price. (West KY is a big dealer in used parts, and many forum members have had good experiences with them.)
2) Talk to a machine shop in your area (okay, "in the city") about repairing it. Keep in mind that the popular notion that cast can't be welded is BS (Bereft of Sense). And some of your neighbors likely will know of someone who can make a repair to it -- farm folk are geniuses at such things!

Obviously, my preferred choice would be #1, but #2 might be more satisfying, if not more frugal.

Best wishes on a quick and successful repair; please keep us informed of your progress!

lakebota · Apr 21, 2015

If I see a broken bolt, I think it can be removed. If the trans case is not leaking, just broken/missing shoulder, I think a new angle iron bracket setting on a shim setting on a new land cut with a die-grinder would work. If you don't have the tools a good shop should be available.

North Idaho Wolfman · Apr 21, 2015

That part is 100% replaceable without a whole lot of work and that would be my choice.
There is 3 different part P/N's for that part, if you give me the serial # I can tell you the right P/N.

New your looking at $684.64 so used should be about 1/2 that.

GaryMc · Apr 22, 2015

Thanks for all of the responses! It's nice to find such a supportive network so quickly, I'm sure I'll run into a few other surprises.

NIW - My serial # is 51934. You're sure this would be easy? My original thought was MAJOR work, hence the "cover up".
Lakebota - Nope, that's the bottom of the hole.
ShaunBlake - Yep, that's JB weld. I'm not sure the owner knew, he owns a Const. co and may not have known the quality of "repairs" that were being done by the help. Thanks for the info on WKTP, I'm sure I'll be checking on this part and others at some point.
Bxray - It sounds like we're on the same page, although I'm not sure the holes below would add much integrity to the repair since the stress being applied is above that point.
Milo - #3 sounds like a great idea. Now, if I could only see my pictures while typing my replies.

FTG-05 Of course not!

D2Cat · Apr 22, 2015

GaryMc, replacement would best solve your problem, but I like making things. Here's what I'd do.

Use 1/4" plate. Reinstall the left bracket to get measurements.

Take rectangular plate and remove corners to match existing angle.

Use existing angles (that top ling pins to) to weld to base plate.

Form tabs that will be welded to the back that will be bolted by existing vertical bolts on the bottom (now behind angle for top link).

Might cut square opening in base plate to reach bolts behind, or you might get them fine when lifting 3pt arms.

Clean out deformed hole and use insert to reuse this hole.

If you get 50-70% strength from this hole you'll have stability with the additional tie in of iron and 2 additional bolts holding bracket.

My drawing shows the iron holding the top link as being formed and welded. In the write up I decided to use existing angle brackets and just weld them to the back plate. So the base leg is not shown in the sketch.

Tooljunkie · Apr 22, 2015

Im guessing all the bolts came loose/fell out except for that one. Thus destroying casting.
I would pull. case off, check for thickness of casting and if at all possible go deeper. Failing that,have a welding shop build it up and re-thread it.
Last resort- find a stud ( wheel stud may be right size) and weld it in, build it up and bolt mount back on.
I have found using studs sometimes work better as they can be threaded to bottom and nuts will apply tension. This way using every thread where a bolt cannot.
Good luck, it sucks when you find something like this sold in as-is condition.
I have seen broken bolts siliconed back into holes to hide poor repairs.

SRS · Apr 22, 2015

Gary, if I'm not mistaking Kubota makes an optional support for this. You might want to try Messicks in PA http://www.messicks.com/tractorparts.aspx and speak to one of the parts tech and ask them about this support. I remember where Kubota made the optional stronger top link bracket but you have to specify the "optional" support bracket. I'm checking Messick's parts catalog now and so far can't find the d@^& thing. Stanley

SRS · Apr 22, 2015

Here are a few links to hopefully help you out. If you don't go with a kubota backhoe reinforced bracket you could make one yourself or have it made. Also on one of the links (can't remember which one) it shows how someone placed X brackets to give the attachment some better support. Good luck, Stanley

http://www.tractorbynet.com/forums/kubota-buying-pricing/155300-cost-kubota-hd-top-link.html

http://www.tractorbynet.com/forums/kubota-owning-operating/9893-kubota-top-link-bracket-part.html

http://www.tractorbynet.com/forums/attachments/261131-3-point-backhoe-reinforcing-tractor.html
Go down to "slowzuki" post and he shows a picture of the reinforced backhoe bracket.

https://www.kubotapartsdepot.com/item/70050-00540/ (not sure if you need to remove the s after http to open)

http://www.goldeneagledirect.com/index.php?l=product_detail&p=163187

ShaunRH · Apr 22, 2015

I'd pull the casting, remove all the faulty repairs, drill out the hole and braze in entirely new metal. If you can go through the casting without bothering much behind it, I'd drill through it and tap the entire length and use a good thread sealer so no oil could come out through the hole.

The brazing would accept new threads and the deeper hole will hold shock stresses better.

The worst that happens is that it breaks again and you have to replace the piece anyway.

North Idaho Wolfman · Apr 22, 2015

The P/N for your Case is 6C200-36034.

If you replace the case I would also make the top link support like D2Cat shows, that would make sure your not breaking another case.

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Broken top link mount

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