Bagger Shear Pin on Kubota OEM bagger

[KeithInSpace]

I have the bagger for the BX1500 to BX23 series machine (I think it changed with the BX1850 to BX24 series) and have always had a heck of a time with the shear pin popping.

I used Class 8 bolts for a while, but it ate them for lunch...2 or 3 a mow.

I switched to split roll pins and it went much better. I could go a mow or two without it popping.

Recently I was mowing and I heard a ticking in the back...though I had broken another pin. What I found was that the shear between the two shafts had compressed the split roll pin and it backed it's way out, hanging on by a thread. Turns out that I probably wasn't "shearing" them at all...they'd just get compressed and fall out on their own. Makes sense since I never found any remnants of the pin in the machine after it broke...always thought that was strange.

This was about the time I took my machine in for a 200 hour comprehensive service. The dealer installed DOUBLE roll pins (one inside the other) and tied them to the shaft with a wire so they can't back their way out.

Two mows and it's still a tight connection. Hopefully that licks the problem.

Thought I'd share since I've seen several others having the same issue.

 

[AMR]

Keithinspace - are you talking about the pin that connects the two shafts in the bagger assembly from the pto to the blower? I can't believe that you would actually replace that multiple times, that is a wicked pain, I would have gone mad, it is a shoulder bolt if I recall correctly. I mowed with my BX23 for 3 seasons and I had that bolt break once, about a month into my first season. So, of course, I bought about 10 of them and never needed another. I can't believe that something isn't wrong if it breaks that much, I even ran over my basketball once and it sucked it right into the bagger and the bolt never broke.

 

[KeithInSpace]

Dunno. Never had the bagger serviced before (just got a trailer big enough), so the gearbox fluid was original. It never felt "tight" or anything, so I'm not really sure what has been going on. It has been pretty constant, though.

To clarify: The pin isn't INSIDE the bagger assembly...it is the one under that square shield plate where the PTO shaft engages the bagger unit.

I've actually gotten replacement down to a science. It takes me as long to stop mowing, drive to the garage, and drive back to where it broke as it takes me to drive a new pin.

Good to hear you haven't had any problems. I have loads of sticks and stuff that have been trouble when the get in the impeller.

Pretty impressive with the basketball. Aren't those usually bright orange?

 

[firec]

I've had the same problem for years with my BX2200. I took the unit apart and everything seemed fine. I've concluded that the mower deck expels more than the blower can handle?

 

[blackmajicwoman]

As I recognize some of you on this post from http://www.tractorbynet.com/forums/kubota-owning-operating/41825-bx-2200-grass-catcher.html , I have concluded that the nut and split washer that hold the shear pin in place need to be taut. As I mentioned in the other post, split washer was worn such that it did not lock the nut in place. This season alone I have gone through 8 shear pins...and only the one that connected the PTO gear box to the shaft (other side shear pin has yet to break!). As KeithinSpace mentioned...I have become real proficient in changinging the shear pin...I can change it out in less than 7 minutes flat! Since I replaced the split washer with a new one, double nutted and locktited the shear pin, I have not had an issue and have mowed three times with this set up.

I believe someone mentioned in the post not to over torque the shear pin, which is indeed tru...but also make sure the nut is not coming loose from the threads on the pin.

 

[AMR]

OK, yup I was thinking about the one inside, that is the one that broke for me, it takes forever to get at it, but bonus is that I did figure out how to change the gearbox oil

 

[KeithInSpace]

OK, yup I was thinking about the one inside, that is the one that broke for me, it takes forever to get at it, but bonus is that I did figure out how to change the gearbox oil

Bummer. I'm sure the one inside is a real pain.

I figured out how to change the gearbox oil, too. $21.97 to the dealership changes it! Magic!

 

[blackmajicwoman]

OK, after breaking a total of (17) 5/16" shear pins on the (PTO side) gearbox-to-shaft connection on my GCK bagger over the last two seasons, my local Kubota dealer and I have concluded that the 5/16" hole (note the tube shaft has a 3/8" hole to house the shoulder of the 5/16" shear pin and a 5/16" hole where the threads of the shear pin come out) has been worn down so much from snapping the (17) shear pins that the pin is not snug, but loose. Thus when the rear PTO is engaged, the 'shear' force added to the amount of 'slapback' cause the shear pin to break after repeated engagements of the rear PTO.

We came up with two plans: (1) remove existing tube shaft, rotate the tube shaft 90 degrees from shear pin hole(s), drill a 5/16" hole through and use a rolled pin to secure to gear box. This option 'could' damage the gear box 'if' too much resistance is seen at the blower end of the bagger. (2) Order a new tube shaft at $139!!!

I figure with all the money I have put into the BX1500, what's another $139...so I purchased a new tube shaft, new shear pins, lock washers and lock nuts. I plan to replace the tube this weekend. I hope this solves the issues I have been experiencing (nothing more frustrating that breaking the shear pin 1/2 way through a mow!). If this doesn't work, I will then kick myself for spending $139 on a steel pipe and invoke option (1)! I'll keep you posted of the results.

 

[Stradbash]

I'll keep you posted of the results.

Please do! I have GKC bagger that I've yet to use and it would be good to be available to avoid the hassle of changing shear bolts/pins often.

Thank you for the report!

 

[mjpalmer]

Is the new bagger a completely new design? I have used mine for over a year and I have not sheared a single pin. I am, however, careful in my engagement and slowly engage the PTO.