Has this happened to anyone else..

[jd670]

I went to hook up my box scraper on my 3320 today and the housing that holds the upper link broke off. I couldn't believe it. Has this happened to anyone else here? It looks like it's made of cast aluminum. Has there been an issue with this happening on the 3320's. Mine is a 2006 model. Would this be a warranty claim? Maybe a defect in the casting. I checked on JD parts, they want $685 for a new housing. I only have 282 hours on the tractor. Check out the pics...

 

[DayDreamer]

The void area at the center is not good and appears to be a bad casting. I think you have a valid warranty claim, but, JD may have a different opinion.

 

[beenthere]

Looks bad. Been cracked for awhile, looks like.
Wouldn't surprise me if Deere covers it...

 

[RoyJackson]

I agree that was a bad casting. That void was most likely the result of an inclusion in the casting which may have caused the failure.
Gotta admit, I am surprise Deere's using an aluminum casting with no steel inserts (bushing) in an area designed to take a cyclic loading.

jd670, bet you wish you had your old 670 back right now!

BTW, don't let 'em weld repair that bracket.

 

[whistlepig]

I have seen this happen on the Kubota B7800. The tractor I own. Kubota makes a reinforced bracket to prevent this from happening although I don't have one. I don't think it happens that often. For sure once would be more than enough. I also think the dark spot in the middle of the break is a void in the casting. If it is a void it would tremendously weaken the casting and cause it to break easily.

 

[Carl_NH]

The top and bottom of the casting is discolored - either from a previous fracture and oxidation or it's a bad casting. This should not happen to cast iron (I dont think this is cast AL) as AL would be a poor choice for this link and JD has been making these for a long time so I suspect its cast iron. If this was a totally "new" fracture, then the casting is definitely bad with the impurities being the discolored portion.

Without some metallaurgy analysis (or a good dealer doing the right thing) you will likely need to put your best effort into getting JD to resolve under warranty.

 

[Thomas]

Interesting..first one I'd seen.
Looking forward to update fix.

 

[whistlepig]

If it truly is a void in the casting as it appears in the picture it is right next to the link hole where his pin is in. The worst possible place. A void in a casting makes it a bad casting. A defective part. I wouldn't hesitate for a second to tell the dealer that this bad casting was the cause of the break. I don't see where they could argue that.

 

[dcyrilc]

I would agree with the assessment of a defective casting. I also question it being aluminum. From the pix, it looks like cast iron to me. The discoloration and the void are not normal for a situation where it was overstressed. I would contact the dealer immeadiately. The sooner they can look at it, the better your chances for a favorable outcome.

 

[zzvyb6]

Without commenting on whether or not the iron/steel casting was bad, I would point out to readers how to reproduce this problem if you are so inclined.

This upper link hinge is designed to take load forces on the axis of the pin in the upper link, not bending moments about the base of the hinge (where it broke). Yeah, its been cracked long enough to get some rusty solution leaking into a partial fracture.

Causing the hinge plate to crack is easy: Just lose the ringed lynch pin in the hinge pin so that the hinge pin can come partway out of the hinge far enough to contact the pickup arm on one side when the lift arm is raised. . The side that breaks will be the side with the cap on the hinge pin, just like you see in the photos. When the hinge pin comes out far enough to contact the lift arm and the arm is raised, it will probably crack or break the hinge plate on that side. There will be a contact mark on the lift arm at about the same location as the one seen on the arm in the photo(s). It may only crack it partway across when it happens, so be prepared to have it fail comepletely when you next apply a typical 3 point load to the draft arms.

Grinding the edges and then welding with nickle rod will make it as good as new.
I always recommend buying good lynch pins instead of the 10 for $1 you can get at flea markets...