Kubota Says No Wheel Ballast With a Backhoe.

[Soopitup]

In my owners manual (BX23S) it says don't fill rear tires with ballast if you have a backhoe mounted.

Curious if anyone has any input on this?

I didn't know and had my tires filled (salesman didn't say anything).
I'm not really worried, it isn't doing wheelies or anything (unfortunately ). I've had the front straight up on a roughly 30* slope and it's fine.
FEL or pallet forks mounted always (so far).

Just wondering if anyone knew Kubotas reasoning?

 

[ZTMAN]

Neil's video may help you:

 

[VaGlock]

I purchased my B2601 used with the BH, it came from dealer with the rear tires filled. I watched the Messick's video and from what I understood it is ride quality that he stated was the benefit of no fluid in the tires. If the tires are filled correctly there is still a air cushion in the tires to provide a cushion. Also if you have a heavy implement on the rear bouncing around on the rear it kind of offsets the ride quality, I know my BH does.
I have not read or heard anything about the possibility of damage from having the tires filled with a BH on the tractor. Willing to learn if not so.

 

[85Hokie]

My dealer filled my BX25D tires from the get go. I have never had the hoe off either.

 

[GrizBota]

If stability front to rear is the concern, Neil has a point about the rear implement providing that balance/ballast. The implement on the 3 point had a much longer lever arm (relative to the front axel) than the fluid filled tires do. So you can get the same effect with a much lighter 3 point implement. Say rather than 800 lbs in the tires, maybe you only need 300 lbs on the 3 point provide the same “balance”. It’s that math thing again. The ratio of the sum of the moments about the front axel need to be a fair bit larger than one, in favor of the rear of the machine. If indeed the primary concern is offsetting the FEL. As there are other benefits of loaded tires.

And I still have fluid filled tires on all my tractors, even one without an FEL.

 

[mikester]

You can always find someone to tell you why the manufacturer is wrong and they know better.

 

[edritchey]

The manufacturer is probably basing it off of the load on the rear axle bearing and seals. I guess they think they will last longer with less weight on them. I have had mine loaded from day one on all my tractors with backhoe attachments and no problems yet.

 

[GrumpyFarmer]

I have read the manual, and discussed with dealer at original time of purchase. Mine was dilevered with liquid ballast, wheel weights and BH installed. I have not seen a reasoning specified though. Manual says not recommend liquid ballast on the rears while BH installed…I wonder why mentions liquid on rears but not wheel weight? I don’t have any intention to drain the liquid to use the BH and add back once the hole is dug. My only thought there is liquid could slosh around a bit if getting too happy with the levers…but I don’t really know. It be nice to know if the concern is stability/tip over concern, or related to ride / cushion (liquid would ride rougher) or is it with too much ballast or related to longevity of axle / seals. Could be something else. Be nice to see an explanation in the manual.

 

[GreensvilleJay]

This is one of those must compare 'apples to apples, NOT oranges' deals. The OP asked about his BX23s.
I have one and the reason I was told,from dealer, is it doesn't need extra weight in the rear when the BH is on. The BH and bucket is 750+- pounds,so you don't need more weight to offset loader operations.
When you do remove the BH, THEN you need more weight for either loader operations and 'maybe' for rear implement use.
Same deal applies when using a BX23s as a lawn mower. You don't cut grass with the loader or backhoe on. In this case ,you remove weight. Makes it easier to cut the grass, better fuel economy.

 

[fried1765]

The manufacturer is probably basing it off of the load on the rear axle bearing and seals. I guess they think they will last longer with less weight on them. I have had mine loaded from day one on all my tractors with backhoe attachments and no problems yet.

"The manufacturer is probably basing it off the load on the rear axle bearing and seals"
......BINGO !!!

 

[Smokeydog]

Bean counter, lawyer, engineer? Who knows? Kubota doesn’t say.

I use liquid ballast and wheel extensions for stability safety on my hillside farm. Local dealer puts rear ballast in every tractor with a loader. They says they have not seen a single problem or had issue from Kubota. Rollovers are no fun. Use your best judgment to keep you safe.

 

[lynnmor]

"The manufacturer is probably basing it off the load on the rear axle bearing and seals"
......BINGO !!!

Weight added to the wheels and tires is not carried by the bearings, it is directly applied to the ground. Seals do not carry weight.

My guess is that Kubota is aware that considerable force is applied to the tires when the backhoe is extended and lifting a load and it may be more than the tire rating.

 

[06B3030]

...when using the hoe, the outriggers should be set so the rear tires are off the ground, and the front bucket set down taking the weight off the fronts. That creates the most stable platform for backhoe use. I wouldn't think having tires filled or not, would make much of a difference when using the hoe, other than the "extra liquid weight" the rear stabilizers are lifting and holding.

With filled tires, maybe the amount of liquid has to vary if you have a BH on the machine, as there is more rear ballast weight and pressure on the tires.

 

[edritchey]

Weight added to the wheels and tires is not carried by the bearings, it is directly applied to the ground. Seals do not carry weight.

My guess is that Kubota is aware that considerable force is applied to the tires when the backhoe is extended and lifting a load and it may be more than the tire rating.

Makes sense

 

[85Hokie]

"The manufacturer is probably basing it off the load on the rear axle bearing and seals"
......BINGO !!!

I dont thinks so - since the axles never carry the weight of the fluid in the tires! ALL the weight, unless you are moving FASTER than the weight can stay below the axle is transferred to the ground and not through the axle.

And doing a bit more research - the added weight could be a roll over addition IF the machine were to hit a tip over point, Newton's second law - F=M*A - more mass moving could, possibly increase the roll past the ROPS stopping you from the next roll.

AND to be quite frank here - with both 26x12x12 tires filled at 75% - you are looking about #150 added total, about #75 per tire, true that is a bit more, but it the same as a 300 pound guy sitting on the seat vs a 150 pound guy.

 

[CGMKCM]

My guess, The wheels are not up to the loads and would crack like some of the TLB guys are reporting.

 

[Trimley]

Lotta speculation going on in this topic, it'd be nice to know the real answer.

Maybe we need an AI Bot.

NO!!

 

[GrizBota]

I wonder what supports the weight of the tires, wheels and fluid ballast when the outriggers are down and the tires are off the ground? But I don’t think it’s the bearings that are driving big K’s stance on the matter. I truly don’t know (getting in line for the AI, sounds fun). But I do know the answer to the marginally rhetorical question I posed.

 

[mikester]

Why is it that nobody complains about tow specs and overloads their draw bars regularly?

Engineers put in a factor of safety on their designs and give you a design load. Let say the FOS is 2x on an ag based TLB. Maybe loading the tires reduces the FOS to 1.5x. Your TLB isn't going to suddenly fail but you might be working the machine closer to its design limits. Materials fatigue is a problem, especially when you are cycling stresses/strains.

Think of bending a paperclip back and forth as an example. If you only apply enough load to bend your paperclip 5 degrees each time maybe you can do this 200x before it breaks. Now if you increase the load 30% your paperclip might bend 15 degrees each way. Keep cycling it and maybe now it breaks at 150x. Insignificant? Maybe. If you were in the business of selling paperclips and people could die when they break, then you would tell people not to exceed the design loads too.

 

[Chanceywd]

When I was making up my order for my L2501 with a BH77, the dealer recommended ballast. I don't know if it was a failure on his part not knowing what the manual says or he believed it didn't matter.
I wonder if it is do to the size of the out riggers and lifting that much more weight. If mine has the back end slightly down hill, it sometimes struggles to lift it. if the front is down hill or level it seems to be lift easier. I checked the system pressure and although it is down a couple hundred from the spec high I wouldn't think it would be that close. I bought the shims etc to correct it but just haven't gotten around to trying that yet.
I like the ballast and wouldn't run without it. Since having it I finally put it in my 73 yo 8N and was amazed at the difference plowing snow.

Bill