Kubota B2710HSD front axel sheared off.

[CalG]

Correct me if I'm wrong but I don't believe the loader will lift anything that will damage the front axles if properly counterbalanced.

wrong

 

[PETDOC]

I have both the owner's manual and shop manual for my Kubota B2710. Neither give a front or rear axel load capacity; however, the load limit for the FEL is 880 lbs and 3 point hitch is 550 lbs.

 

[5030]

In my opinion, overloading a front AXLE is very commonplace not only with smaller units but large ones as well. I've 'overloaded' the front axle on my M9's many times but I am also aware of the ramifications of doing just that and I don't ever have a 'counterweight on the back either which, in my opinion contributes to the eventual failure which in my case was the outboards on my open station M9 at 5500 hours. Could it have went longer without failing? Maybe, maybe not. Mechanical assemblies do wear out after all. Some sooner, some later but all of them do at some point. The insert bearings on mine got sloppy and contributed to the failure and I replaced everything before the issue got so bad that it destroyed the gears.

 

[PETDOC]

In my opinion, overloading a front AXLE is very commonplace not only with smaller units but large ones as well. I've 'overloaded' the front axle on my M9's many times but I am also aware of the ramifications of doing just that and I don't ever have a 'counterweight on the back either which, in my opinion contributes to the eventual failure which in my case was the outboards on my open station M9 at 5500 hours. Could it have went longer without failing? Maybe, maybe not. Mechanical assemblies do wear out after all. Some sooner, some later but all of them do at some point. The insert bearings on mine got sloppy and contributed to the failure and I replaced everything before the issue got so bad that it destroyed the gears.

The bearings on my right front axel were fine. Actually my theory on why the axel sheared off may be tested in a few days. Replacement for left front axel arrives tomorrow. If the original left front axel has no cracks or indications of wear then M59’s posts will be spot on—need more data. When seeing my FEL's weight limit of 880 lbs I had a queasy feeling of 'did I ever overload my FEL?' Not really sure a full load of wet shag bark hickory (probably the heaviest wood I transported) would exceed 880 lbs.

 

[rScotty]

The bearings on my right front axel were fine. Actually my theory on why the axel sheared off may be tested in a few days. Replacement for left front axel arrives tomorrow. If the original left front axel has no cracks or indications of wear then M59’s posts will be spot on—need more data. When seeing my FEL's weight limit of 880 lbs I had a queasy feeling of 'did I ever overload my FEL?' Not really sure a full load of wet shag bark hickory (probably the heaviest wood I transported) would exceed 880 lbs.

In your original post you said,

" Over the years, I’ve hauled a lot of very heavy sections of trees from the site of a fallen tree to my log splitter. This is often been a trip of one to 2 miles on a gravel road. My assumption is that when cruising back to my place with a full load, every time I hit a bump the loaded bucket would transmit a sudden tremendous force on a narrow point of the axle....."

I'd say you nailed it with the bump theory. Those dynamic forces are far larger than the FEL load limit.

rScotty

 

[ruffdog]

In your original post you said,

" Over the years, I’ve hauled a lot of very heavy sections of trees from the site of a fallen tree to my log splitter. This is often been a trip of one to 2 miles on a gravel road. My assumption is that when cruising back to my place with a full load, every time I hit a bump the loaded bucket would transmit a sudden tremendous force on a narrow point of the axle....."

I'd say you nailed it with the bump theory. Those dynamic forces are far larger than the FEL load limit.

rScotty

^^Exactly! Speeding across rough terrain will greatly increase the loads induced to the equipment. With no suspension to dampen those shocks, it will be the weak links that fail, like an axle.

 

[old and tired]

Sounds like the front axle took a lot of stress over time, especially with hauling heavy loads on rough roads. ....

Reported as a spammer!!!! All their posts are....

 

[5030]

Time to add an hydraulic accumulator to the loader circuit. Actually any hydraulic line the feeds the loader will work but the ideal location would be the line that feeds the valve block.

 

[DarkBlack]

Even if the manufacturer provides a written limit for front axle load how are you going to know when you have reached it given the mounting points of the FEL and their relationship to load transmission to both front and back end of the machine. That is exactly why, after Kubota America's engineer refused to provide me with a hard number, I realized knowing the number would not tell me what I needed to know, which is "What is the weakest link between the load carried by the bucket of FEL and the rest of machine. This is a FEA problem. Is it the loader arms, is it the loader arm pins, the bushings, etc, etc, etc.

You found a weak link ( the spindle to hub attachment ) but why must be answered if you are trying to craft a solution that assures a non repeat of this failure and there are many reasons for metallurgical failures.

When it comes to determining force on the front spindles, the attachment point of the loader arms to the tractor frame is irrelevant, assuming the tractor is ridged. The force on the spindles is most directly impacted by the weight in the bucket, and that weight’s distance ahead of the spindles.

 

[DarkBlack]

You are correct on the newer version of the front axels (see pictures); however, the older B series can't use the newer version of the front axel. Axel type is based on tractor serial number. You've got to dance with the one that brung you.View attachment 2307203View attachment 2307206

There may be no visible physical changes, but they might have changed/improved the steel type, heat treatment and tempering.