Drive Shaft - BX2816 50" front snow blower

[Jeff Poplar]

Hello Orange Tractor Gurus:
My BX2816 blower (SN 21910692) drive shaft front u-joint failed after under 50 hours of rotation. My local Kubota Dealer says a new drive shaft will cost $347.00.
Question: I have been told that this is a common problem with the BX2816 snow blower. Are there better (perhaps aftermarket) replacements for this obviously not built for purpose drive shaft?
I should probably also note that all periodic maintenance has been religiously performed on both the blower and the k-connect assemblies.

Thanks

 

[jkrubi12]

Damn, sorry to hear about this, the BX2816 was one of my 'target' snowblower choices!

Do you think that the 'accuracy' of the current mounting process has anything to do with seemingly premature wear? Is a mounting discrepancy even possible with the BX2816 system? Could it be possible that the weight of the blower itself is an overmatch for the mounting system? Do you have any plan to adjust or modify the mounting system (or other components) to prevent this from occurring in the future?

Sorry for the lack of solutions offered; I'm just interested in hearing from an knowledgable user about their experiences with the system.

Any pics you could post here would likely help members in diagnosing any issues. I, for one, would like to stay informed on the issues you are experiences with this system.

Good luck, thanks in advance!

 

[Jeff Poplar]

Damn, sorry to hear about this, the BX2816 was one of my 'target' snowblower choices!

Do you think that the 'accuracy' of the current mounting process has anything to do with seemingly premature wear? Is a mounting discrepancy even possible with the BX2816 system? Could it be possible that the weight of the blower itself is an overmatch for the mounting system? Do you have any plan to adjust or modify the mounting system (or other components) to prevent this from occurring in the future?

Sorry for the lack of solutions offered; I'm just interested in hearing from an knowledgable user about their experiences with the system.

Any pics you could post here would likely help members in diagnosing any issues. I, for one, would like to stay informed on the issues you are experiences with this system.

Good luck, thanks in advance!

See four pix attached. First two pix are copied from "The Technician" YouTube video entitled "Kubota BX 2816 (8 hour) snowblower maintenance and tips!" - Very good video for BX2816 / K-Connect maintenance. Last two pix are of the failed shaft and the new shaft.+
The failure occurred in the main shaft coming from the mid-drive of the BX2680. Both shaft-side and one spline-side bearings exploded leaving only the unharmed yokes attached with all those bearing parts lost in the snow. Failure could be due to the seemingly "un-snug" K-Connect mounting design, but I suspect the K-Connect rear-facing male spline is the bigger culprit. It is very long, and may not have adequate overlap with the female spline of the drive shaft. The design may be allowing excessive drive shaft "whip" action, possibly exacerbated by the flexible carrier bearing going through the rear of the K-Connect which mates up with the U-Joint, etc. etc. that connect to the blower itself.
Just came home from the dealership with my new shaft. The new shaft U-Joint bearing race O.D. is about 5mm larger (24 vs 19mm). I guess Kubota has recognized the drive shaft reliability issue. But as stated earlier, I do not believe this change in bearing size alone will totally solve the problem. F Y I, the dealership parts guys confirmed they have sold "several" replacements due to the same failure symptoms.

 

[GreensvilleJay]

sure is a beefier Ujoint... perhaps they get destroyed due to excessive obtuse angle (bent too far ) ??

seems like a LOT of exposed spline in the first picture. does the half shaft actually move THAT far ??
kind of hard to 'see' the geometry of how the power is transmitted.

 

[Jeff Poplar]

sure is a beefier Ujoint... perhaps they get destroyed due to excessive obtuse angle (bent too far ) ??

seems like a LOT of exposed spline in the first picture. does the half shaft actually move THAT far ??
kind of hard to 'see' the geometry of how the power is transmitted.

There are always several centimeters of K-Connect male spline shaft exposed. The limit of travel is the female spline of the drive shaft. As you can see, it's a pretty significant mis-match (my opinion).

Suggest watching "The Technician" video. You can search for it by the title. (Didn't have any luck including the link without including a huge screen shot of the video. (Maybe a bug in the Orange Tractor Talk web page formatting).

 

[DustyRusty]

I have a BX2816 snowblower, and it has had 2 years use on it, one by me, and one by the previous owner in New Hampshire. I see no wear on the u-joints, and in my almost 20 years of snow-blowing with a Kubota BX, I have never had to even replace one u-joint on a driveshaft. I would have just installed a new u-joint in the old shaft and continued working.

 

[Jeff Poplar]

I have a BX2816 snowblower, and it has had 2 years use on it, one by me, and one by the previous owner in New Hampshire. I see no wear on the u-joints, and in my almost 20 years of snow-blowing with a Kubota BX, I have never had to even replace one u-joint on a driveshaft. I would have just installed a new u-joint in the old shaft and continued working.

I think this failure may be something unique to the K-Connect setup (roughly described and shown above). How long has that been around? As for the drive shaft repair, I am not sure of the procedure of replacing the bearings and races, or whether you could even find a kit to fit Kubota's drive shaft. Perhaps you can fill me in? If it's possible to repair the original shaft (albeit with the smaller bearings) I would at least be able to keep a spare if ever needed.

 

[jkrubi12]

Took a quick look on YouTube and found this, which I believe is the video referenced by Jeff:

 

[DustyRusty]

Look for a local company that sells Spicer products. They will be able to fix you up with the proper parts. As I said, I have the same blower and have never had a problem.

 

[GreensvilleJay]

After re-re-reading this post, the light bulb came on...well it may have...
The clues are... bearing caps are gone, several replacement driveshafts sold, no cap retainers

If the cap holes in the yokes were machined just a wee bit too big, the caps are not tightly pressed into them and can then come out easily. Maybe when presssed in, they weren't 100% dead on ? original ones don't have a lot of 'meat' (metal ) surrounding the cap,so it can be easily deformed and/or stressed, so not a TIGHT fit. The new ones have more material ,yet now retainers.

Unlike car ujoints, these units do NOT have the bearing cap 'retainers' so there is NOTHING to prevent centrifugal force from spinning the cap out of the Ujoint. Any 'looseness',even 1/2 thou is bad when combined with high speed (1,000, 2,000 RPM ?) and vibration then over some time...bang.. a cap leaves...

 

[DustyRusty]

Never lost a cap on a tractor driveshaft, but if I were replacing a cross bearing (u joint) that didn't have a cap retainer, I would use some Loctite to keep it securely in the end yoke.

 

[atitus]

I have the Kubota front blower I bought it in June of 2018 with the tractor. Not sure if this helps but I'll attach a picture of the u-joints on the front pro shaft. I just happen to be putting this thing on the tractor while I saw this thread so I figured I'll grab a pic. Im no expert on how these things are assembled but there is definitely some sort of cap over the retention clips or whatever. Looks press fit.

 

[atitus]

For comparison purpose here is the u-joint from my mowing deck, also bought June 2018. Here you can see the retention clip straight up, this is true for both sides of both halves of the joint. So I guess it's possible they all fell out but that seems unlikely

 

[GreensvilleJay]

A, 1st picture, there is no cover or retainer, that IS the bearing cap.
A good 'parts' diagram may show the 'bits and pieces' ,would need part number of unit though.

FWIW, looked at a BX2811, 70060-02186
shows parts, complete 'cross', yoke but NO retainers

so it'd be easy to see how the caps can come out.

 

[atitus]

Thanks Jay that's interesting. I wonder what drives the choice between the classic clip retainers vs those others. Just a pure price thing? The mower deck will operate through a wider angle range though I try to remember to lower the deck before spinning it up and disengage before raising all the way but sometimes I do raise it at full rpm to avoid ground obstacles when mowing.

 

[DustyRusty]

sometimes the caps are kept in place by small nylon pins that are pressed in from the sides. GM used that design and the replacements use clips to hold them together.