L3710 3 point ripped out of housing

[woodman55]

Rockshaft is broken as is rear differential and housing. Looking like $7500 to fix.
Is a L3710 with 800 hours on the clock worth fixing? Seems like a nice tractor but know nothing about if it’s a good model for Kubota?
Photos pre damage

Pretty sad seeing a good tractor tore up.

 

[SDT]

I've done FOUR of them, all the same exact failure. Looked identical except they were all FOUR on the same tractor (MX5100). I know an MX5100 is different than the OP's tractor but the principles of operation are identical.

Of those 4 times, I asked the owner what happened and of course the normal answer was "well I was just driving across the field....". The LAST time it happened, I told him either someone's gonna have to give us better idea what actually happened, or we're gonna just have to refuse it the next time (and I was kidding about that last part, and he knew it). He said the same thing, he was driving across the field and it just broke. This was backed up by the kid who was watching his dad cut grass; but the kid went on to say that once the last row was done, he turned around, threw it in highest speed it's got and about throwed the daddy off of the seat several times. Ah-HAH!

Before we (or should I say "I") condemned the operator as the cause, I consulted with the kubota central division service manager at the time. Super good dude, excellent communication skills and superb knowledge-and memory. Explained the situation and the very first question he asked was this. Was the tractor driven at high speed on rough terrain?

Yup...confirmed it. BOUNCING.

Think about it. The weight of a 6 foot shredder is significant, but it's how far back the weight is hanging on the 3ph that causes the issue. It's 6 foot back, and acts like a long lever. Get it to bouncing and something's going to give, it has to. The lower links and their mounting points are pretty stout. The upper part is too, but it's not as strong as the lower. Secondly if the 3ph feedback linkage is out of adjustment and is pouring hydraulic pressure to the cylinder such that it bottoms the piston out in the bore, it is still pushing the rockshaft, and there is significant pressure pushed toward the rear of the tractor which combined with bouncing, something's gonna give and it's almost always the 3ph cylinder housing.

once we discussed this with Mr. Customer, he was totally understanding why it was happening. He'd get the tractor home, feedback link adjusted properly but to him, it was never enough lift, so he'd adjust it some more so the shredder would lift that last inch. Well then bounce it a little (or in his case a lot), and it broke the housing. Every time. Now that he's educated, he's slowed down and left the feedback rod alone, and to my knowledge hasn't had an issue since.

Bingo.

Not designed for such abuse.

Vintage Fords have a so-called "safety valve" in the lift cover to protect against such abuse.

Don't know about Kubotas.

 

[mcmxi]

Think about it. The weight of a 6 foot shredder is significant, but it's how far back the weight is hanging on the 3ph that causes the issue. It's 6 foot back, and acts like a long lever. Get it to bouncing and something's going to give, it has to. The lower links and their mounting points are pretty stout. The upper part is too, but it's not as strong as the lower.

It is interesting to look at maximum 3-point lift specs and then at maximum 3-point implement weights. Kubota is trying to account for dynamic loading no doubt, but as I show below, the manuals are questionable to say the least.

I see lots of tractors running big, long plows on the back and see the tractors oscillating front to rear (bouncing) when the plow is out of the ground, without damage to the rear of the tractor. If the front of the tractor isn't allowed to move since it's chained down to a trailer, and the rotary cutter is basically suspended in mid air, this is probably the worst case scenario in terms of the load on the castings at the rear of the tractor as the cutter bounces up and down.

I've poured over the manuals for both the MX and the M and it's a $hit show how these manuals are put together. There's no rhyme or reason to some of the specs. For example:

M6060
Max lift capacity at lower end link > 4,189lb
Max rotary cutter width > 84"
Max rotary cutter weight > 1,200lb
Max flail mower weight > 1,760lb
Box blade max width > 72"
Box blade max weight > 1,000lb

MX6000
Max lift capacity at lower end link > 2,870lb
Max rotary cutter width > 84"
Max rotary cutter weight > 1,000lb
Max flail mower weight > 1,100lb
Box blade max width > 72"
Box blade max weight > 1,000lb

So an MX6000 is rated for a rotary cutter that's 83.3% the weight of an M rotary cutter but is rated for a flail mower that's 62.5% of the weight of the rating for the M? The manuals are full of these types of discrepancies. Oh, and according to the owner's manuals, the M and MX have the same rating for box blade widths and weights!! Yeah, right.

 

[mcmxi]

Long story here, but I paid someone to ship my fathers Kubota to me in Montana. It appears the shipper ran a strap over the brush hog while hauling. Too much pressure or something but it ripped the 3 point out of the housing.

Tractor has less than 1000 hours on it so am getting it fixed. Looking for advice and possibly what $ I’m looking at for repair.

total bummer…. View attachment 89764 View attachment 89764 View attachment 89765 View attachment 89766

That's a really cool tractor and awful to see the damage which appears to be a result of ignorance or stupidity on the part of the shipper. If it were me I would definitely get it repaired and possibly pursue legal action against the shipper to cover expenses.

 

[GreensvilleJay]

1911, those numbers kinda make sense...
if the MX is an 'economy' version of the M, then LIFTING capacities would be less....

 

[mcmxi]

1911, those numbers kinda make sense...
if the MX is an 'economy' version of the M, then LIFTING capacities would be less....

I'm not questioning the lifting capacities, only the implement weight ratings.

I don't mean to take this thread off into the weeds, but @lugbolt made a good point about the weights of implements and where that weight is situated relative to the lifting points on the lift arms. Like I said, the weight ratings for various implements are much lower than the maximum lifting capacities which makes sense since Kubota has to consider "typical" use and dynamic loading vs. static loading.

I've made the point that chaining the front of the tractor down makes the situation much worse than driving around a field with a rotary cutter raised up off the deck, since in the latter situation the front is able to move upwards which acts as a shock absorber (energy transfer). Someone has made the point here in the past that it's better to keep the wheel(s) on the ground when moving with a rotary cutter and I agree with that. Sometimes you have to raise the cutter off the ground such as when getting on/off a trailer, but that's a slow maneuver so less likely to cause damage.

This thread really makes me think about all the stress on the rear of the tractor and we all need to be careful and thoughtful when using our expensive tools.

 

[Mak65]

Sorry to see the damage. Hopefully the hauler can be held accountable and cover some if not all on insurance.

I only have an L series but after reading this I am no longer running across the fields with my mower elevated. Strictly running on the tail wheel from now on.

Good luck with an outcome.

 

[Old_Paint]

It’s back there flopped all the way down past the ramps. I suspect it was damaged while loading?

Oh my. There was nothing supporting the tail of the RC. That's a lotta weight bouncing on the 3 point hitch. At the very least, the top link should have been removed to let the RC go down on the dovetail. Dunno how that could have been done, but it might have saved the lift.

Best of luck, and hope their insurance pays.

 

[Golight]

What backhoe model would fit this? Does Kubota still make a compatible one or am I looking at aftermarket?

 

[North Idaho Wolfman]

What backhoe model would fit this? Does Kubota still make a compatible one or am I looking at aftermarket?

Your best bet would be aftermarket, Woods is a good model to check out.
A subframe model would be the only one you want to look at.

 

[Golight]

Parts ended up being $4200, shipper ended up going home with no pay from me. Total ship bill would of been $7500. We called it a wash and I’m paying for repairs. Probably have it back in a few weeks. Final damage pics:

 

[GeoHorn]

$7500 shipping..?? From WHERE did it ship? Was that the quoted price when the shipper was contracted?